Had you worked in a competitive environment similar to academia before your PhD and enjoyed it? If that was the case, then I'd say maybe a postdoc in a different university might be ok (although remember postdocs get a lot less supervision and support than PhD students do). It might be though that you are just not suited to working in highly competitive environments, in which case definitely look elsewhere - ruining your health over a PhD or job is not worth it. Academia is not the right environment for a lot of people, and the pyramid of ever decreasing jobs at each level means that the competitiveness doesn't go away - it's very target driven these days even for top professors.

One possible reason might emerge if you google the Lacour / Greene mess. I imagine a lot of senior folks will be more wary of publishing now when they know their name is on the paper because they are famous, not because they've really contributed to the paper. Not that I'm suggesting that you've fabricated data of course, more that I think very arms length collaborations like the one you outline are being frowned on a bit these days, and maybe that is why he's changed his mind.

I don't know whether this might reassure you a bit, but increasingly the reference letters I write for former students are requested after the person has been offered the job, and seem to function more as a confirmation of qualifications etc. That's for non-academic jobs, but even for academic jobs, references are rarely requested before someone is short-listed, simply because it's easier to contact the referees for 5 people, than it is for everyone. In other words the reference letter might not be as big a deal as you think.

Human geography is so broad, that you might be able to pursue your interest in environmental history in your undergraduate dissertation, so your current degree may be a little more flexible than you think. If you did something like that then maybe moving on to a relevant history MA might be an easier argument to make the case for? And have you looked at final year options yet - if you can do modules around post-colonial geography or things like that you might find you get a surprising amount of historical content. Obviously if you loathe geography then you might be better dropping out an reapplying, but I didn't get that impression from your posts.

Book chapters are nice extras, but journal articles are of greater value in almost all if not all fields. If you are hoping for an academic job, then I'd always favour putting your efforts into getting articles out over book chapters. My own employer for example has told us that book chapters won't count towards a REF submission, so if you are in the UK, I'd think very hard about it.
How do you get to write a book chapter? It's by invitation from the book's editor(s). Sometimes they come out of participation in a small workshop where an edited volume is planned as an output. Sometimes you get asked because you're regarded as the expert on something (or the most likely person to deliver a respectable chapter on time). Edited book projects can be a long time in the making, so it's often not a very quick or reliable way to get published.

Ellebelle I think the late submission may be inevitable now, but see no reason why you should incur the extra fee. I would suggest emailing the head of department explaining the situation (do this very calmly and with understanding for the 2nd supervisor) and ask whether s/he can intervene to ensure that you are not charged the extra fee, as it will cause real financial difficulties for you. Are you RCUK-funded? If so, and this is the four year deadline point, they really should be bending over backwards to somehow bend the rules so you don't count as late submitting in their returns. HoDs tend to be more strategic than your average academic about rules and more likely to know who to ring to fix matters.

We probably need a bit more information on what sort of job you hope to get, and if academic roughly what field but a few general thoughts:

Get both an academic and a non-academic cv drawn up and get advice from the university careers service if they have someone who specialises in PhD candidates - mine did and she (and my supervisor) were very helpful in stopping me making some rookie errors on my academic cv in particular.

Think through the parameters of the job search (and make sure any partner / family are on board too). Where is it ok to apply - international / national / local? How long are you prepared and able to hang out for your preferred job? What's a good plan B / C /D? Are there financial restrictions e.g. you can't hang around doing part-time hourly paid teaching as you need to pay a mortgage? Make sure those around you understand how hard it is to get an academic job - I could have murdered several of my nearest and dearest for their utter failure to understand that. I think if you do some of this thinking ahead of searching you (and partner/family) are better prepared psychologically.

Try to see what people have on their cvs who have been recently hired into jobs you'd like. Do you have any obvious gaps and if so can you fill them during this year?

Finally if humanities / social sciences and wanting an academic job, make sure you know about the postdoc funding schemes out there and what the deadlines are. Those applications need a LOT of forward planning.

Manchester isn't the only university to not accept pass Masters degrees for a PhD - my own institution has the same rule for humanities and social sciences at least, as experience has shown that such students tend not to finish the PhD, which is bad for the university's completion rates. A merit would given more opportunities, but unlikely to produce funding. You really need a 1st or a distinction at Masters to stand a realistic chance of ESRC funding.
There are many ways in which you can work on development issues without it being on the research track. Indeed a lot of development studies research has no impact whatsoever, if my practitioner friend is to be believed. It might be that your skill set is best suited to a more practical application of development work. I'd certainly be hesitant about assuming a PhD will do anything for your employability in that field, and agree with the others that you need to think long and hard before you invest time and money into self-funding a PhD. I'd double and treble the run away now advice if the courses you've found difficult are methods or theory courses, as you'll really need to be good at both to survive the PhD.

It sounds to me like something bad is happening in your supervisor's life right now from the description you give. I'd get help from the second supervisor as RinaL suggests. It also sounds though like you are engaging in catastrophe / all or nothing thinking - might it be worth seeing if you could get a few sessions with the university counselling service? The last couple of months are horrible anyway for most people, but it sounds like you are suffering emotionally more than most, and maybe talking things through with a counsellor might give you some extra support.

I imagine it might be because of time sheets. Some project funders, e.g. the EU, demand time sheets, for all full-time project employees, to prove that they are actually at work. If you have a flexitime system, then it's loads quicker to gather and send that information than it is to force each postdoc to fill in a daily form by hand. That at least is why I was on flexitime as a postdoc.
You know this won't go away? All full-time academic staff in the UK have to do something similar - every couple of months, you have to detail a full week's activities by the hour. This is demanded by the government to track what activities academics are spending their time on. It is really annoying. Additionally, there are some universities (I've heard Surrey is particularly keen on this) that demand academics are in their offices between certain core times i.e. most of the standard working day. Depending on who you work for, the claims that academia is a workplace where you determine your own working pattern are definitely fading.

Well hourly paid work rarely gets advertised openly so unless you're on the dept's radar, you're not going to get it. I know my HoD gets lots of speculative applications and while mostly nothing comes of it, he does keep a file of cvs in case any emergencies hit. I'd just send a cv and a short letter saying what experience you have, what you can teach and ask if your cv could be kept on file in case any suitable teaching becomes available.

Bilbo is absolutely correct. A transfer isn't going to be viable. Swallow your pride and anger for now and just do the corrections and get the degree. You don't need to have anything to do with academics / universities etc after that, but it would be a waste of years of hard work to walk out now.

I'm guessing that you are humanities / social sciences if you have a book chapter so I think what you need additionally is a plan for postdoc applications, as you've probably realised lectureships don't tend to go to brand new PhDs and most need an interim postdoc. You need for instance to think about potential hosts for Leverhulme / Marie Curie etc postdoc applications as you need institutional backing to be able to apply to most schemes, and to stand a chance the applications need a lot of work with the postdoc supervisor. Otherwise top quartile journal articles are the currency that gets you short-listed for research intensive universities so be very strategic in where you submit your work. This assumes that you are not geographically restricted - if you are then I'd also prioritise targeting commutable post-92 universities with your cv as they tend to have fewer PhD students, and so more need for last minute sessional teachers, and the teaching intensive places seem more open to hiring from their existing part-timers - or at least several posters on here claim this is the case (I have only worked at research intensive places where this isn't true so this is hearsay).
I'd also suggest working on plan B during the year - what can you do to make yourself employable in a job that interests you, if academia doesn't come calling? I've seen far too many bitter PhDs stuck in hourly paid teaching jobs years after finishing, not to think it's wise to have a viable plan B, and to set a limit on how long you will hold out for an academic job.

Kathryn - however hard it is, I think you have to move on from wanting an academic job. Others have said that if you are seeing everything you go for as an unappetising plan B, then you're probably not presenting yourself as well as you can, and I think although the message is hard, they're right. Can you step back from defining yourself by your qualifications and think about what elements you'd want in a job to be happy? Maybe if you applied for things you'd like to do, rather than things you think you ought to apply for because of the fit with your background, it would be less of a stretch to be enthusiastic in an interview. That 'what colour is your parachute book' is irritating in many ways but maybe working through something like that would help you to think more positively about your options.
No idea what sort of research you did, or what type of industry there is where you live (and if staying there is important as it clearly is to you, then that is a life choice - one that might limit things but we all know there are pay-offs in life) but how about university administrative jobs (rationale - there are some interesting ones and they are open to employing PhDs), scientific civil service (again lots of Phds), are you close enough to retrain slightly as a data scientist for the big data jobs? Or might you like teaching better if it was f/t in a school of your choosing? There's a shortage of maths teachers apparently and a comp sci friend did a subject enhancement course to let him teach maths, so that might be an option.