lol, yeh, that would sorta be helpful...

I would pay absolutely no attention to Crions!

This is a really difficult situation to be in. Can you get some second opinions on your thesis by showing a summary of it to other academics? It would be especially useful to have this since you don't sound 100% confident in your supervisor's experience / ability to advise you on the do-ability of your project. The thing is - you are so far in - have you actually carried out the research and got some results (whether the ones you were expecting or not). Do you have something that you can shape in to a coherent thesis / a story? I am wondering if that needs to be the priority now - plan thoroughly / figure out how you will shape your thesis into something coherent - so that you then have the confidence to write it.

If you can meet with a few people or discuss over email - and get their take on your thesis - that'll really help. It would have to be someone in your research area of course. But there are helpful people out there. If you just explained your situation and asked if they could offer some advice. You could make your supervisor aware that you intend to do it. I'd be trying to find a few people in the hopes that one is willing to lend a bit of their time to give their thoughts on it. If someone could help you in that way - by validating your thesis / story as worthwhile and worthy of the award in some small way, you will feel a lot more confident about writing it up.

I haven't seen all the responses but ... if a supervisor did not make you quit in the 2th, 3th years because you don't have the potential or very bad works. Why would he do it now when you only are a few months left in the program, right?

I think what he means is that your work may not be as good as he expected, and most likely disappointing / far behind. That you need to reconsider this career down the road because your peels are better and he may think you are not competitive. Being said that, he is not asking you to quit but just giving you a real feedback? Remember professor is not only your supervisor but a mentor for your professional. He has responsible to bring up his students, otherwise not only look really bad for you (quit on 4th yr), but on him professtionally.

I would disagree about taking the supervisor opinion as a final assessment of your prospective career in research. We all have ups and downs. You may not have performed excellently in your PhD but this does not mean that you will "never" be a good researcher. You can learn from the experience and improve.
I know some guys who made excellent work with publications in prestigious journals in their PhDs and they have not performed as expected later. The PhD is a step and your supervisor has no right to "expel" you from academia. Of course you should take his critisim into consideration but only to improve not to lose your confidence.

Since you have only a short 6 months left, why don't you just give it one last a shot? Sit down and plan your thesis writing with your supervisor. Rather than quit, try your best and in the worst case scenario, you will end up with a MPhil rather nothing. You are training in your PhD, not trying to get a Nobel prize. It is understandable that things may not be smooth, and sometimes, there may not be much results to show for your efforts due to circumstances. It is hard, but do hang on just for a little while longer.

Have a short break to renergise. Then reengage with your supervisor to set the thesis outline and your milestones to get all the work done. If your supervisor is one of those absent types, then get another experienced researcher to have a look at your outline. Invest in a proofreader if necessary and get a friend to read your chapters if you could. All the best.