I'm sorry you're having such a bad time. I am in a very similar position to you. I completed my viva two months ago and have major corrections to make. It feels insurmountable at times and I cry most days.

Some things I have found helpful. Take your list of corrections out of list format, put them into excel rows under chapter columns. That way you're not over-faced with a whole list of stuff that needs doing. I also colour code them when complete so that I can see progress.
I also find speaking to other academics useful - everyone seems to have a PhD/viva/corrections story that is often not positive and they made it through. I guess really, I mean keep going. I hope the balance will tip soon and it'll be a distant memory. You may not feel positive about your future just now but one thing is certain: your career prospects will look a lot better with a PhD! Good luck.