I think the regulations are only guidelines.
In order to ensure parity with previous years, grade boundaries can and do move around. 70% may not be enough. Conversely 68% might be enough in some years. It works like this at school level too.
Someone here who is involved in marking might be able to clarify but I think I am right here.

I won't lie, reading about chasing increasing H-factors, citation scores and impact factors makes me glad I quit academia. I can feel the life being sucked right out of me just reading it :)
As an aside though, I am sure that self citations don't count towards any scores. That would be open to all sorts of abuse.

At this late stage you probably don't need your supervisors help anymore. I would resist further contact, write up and leave.
I'm afraid academia is peppered with these absolute bastards and you are better off getting finished and away.

I'm afraid tru is correct. If your supervisor won't back you, you are in a very difficult position.
You should at least have your supervisor answer your question about why he has changed his mind.
I suspect he has been over-ruled by his department. Is he a new researcher?

In which case you might be worrying for nothing.
It would have been a lot worse if those results had predicted something which had to then be fully refuted. THAT may have justified a rewrite.

Blaming her is misguided.

It's your PhD, your thesis and your viva defence. You are going to be challenged on what you did and why you did it. Saying that you did it because you assumed your supervisor was correct and that you didn't subsequently and independently verify her advice would be a disastrous strategy. You need to think through exactly what you are going to say when asked about this. The viva is there to check that you have personally done the work and made the crucial decisions. A major slice of your thesis has fallen foul of this.

If you don't see that my pointing this out to you in advance of your viva and warning you what to expect is helpful to you then that would be a real shame.

I suspect none of us are medical doctors on here and can't really advise on what is a personal medical issue. There could be withdrawal symptoms and other related side issues which none of us are likely to know about.

You should really discuss this with the person who thought your condition was so serious that it required medication to help you in the first case.

I would be re-writing my thesis to make these changes right now.
That way you are already ahead of the curve in terms of fixing things when you have your viva.
Rewt is right that your analysis of dodgy statistics is worthy of note but none of us can ease your mind over how your external will view that. Already being ahead of the curve and being able to demonstrate that during the viva will definitely help you.

As an aside, I always advise against people blaming their supervisor for mistakes like this. At this stage you are expected to know what you are doing and why. You are expected to be an independent researcher now. You shouldn't be relying on your supervisor for core parts of your thesis (and what you are describing is certainly core). That falls squarely on your shoulders I'm afraid. It sounds like you are owning this now though and are making the changes required.

Not so sure about point 3. Whilst you don't want to waffle, you do want to give fairly expansive answers.
This demonstrates a wider knowledge of the relevant areas and helps you satisfy the examiner more quickly that you possess the attributes required to pass. More importantly it reduces the number of questions they can ask and eats up time.

SaltyAbs, you really need to be focussing more on the research group whose work interests you the most rather than on the university. Then having identified suitable groups you want to evaluate the computational resources they have access to.

Yeah you are correct here rewt. It's not about the hours you put in, it's what you get done in them. If Ellenh is good at compartmentalising stuff and can focus completely during the PHD working hours there should be no problem. If she has a good support network of other people who can help out with the children that would be ideal.

I think my original post was maybe a bit too negative.

If there is a moderator online, you need to do something to try and help this poster.
The IP address used by the original poster to post that suicide note will be in your server logs and you can trace the country of origin and ISP from that. You should pass that onto the relevant police authority from that country immediately and ask them to trace the person. They should be able to do that with almost no effort whatsoever through the ISP.
Monkiaa is still alive as can be seen from the last login so really this needs urgent action.