Hi anon007,

I can also only relate my experience but I hope it helps. My mother was diagnosed with incurable, but controllable, cancer before I started my PhD. It was controlled with some treatment and pain management until last April when it became very aggressive and she needed correspondingly much more aggressive treatment and several emergency hospital admissions. At this point I was 14 months into my PhD. According to her consultant she responded well but she felt absolutely awful and needed a lot of support this last year. Last month, after another emergency hospital admission, we learnt that the aggressive cancer had returned. She died 3 weeks ago.

I completely relate that you are concerned that you may not be able to finish your PhD. I made the decision in July last year to go part time (I am funded and my funders have been supportive) and if I had not done this I would not have coped at all. As it was I was able to upgrade in December last year and am (somewhat) confident that I will complete. I could also provide support for my mother without wrecking myself. These are some of the other things I found / find useful:

Asked my supervisor to help me break down really complicated tasks into manageable chunks.
Cried in my supervisor's office and didn't worry about it.
Regular exercise (in my case cycling).
Counselling (find a different one if the one you have doesn't help).
Told people what was going on.
Worked more when things were easier and didn't work when it was too tough.
Only do easy, dull things when my concentration or confidence is worst.

I am not intending to return to full time, I will take just under 4 years instead of 3 and I am happy with that.

It's tough. There is no 'right' thing to do. It does sound like you have good strategies but you will probably still wake up at 3am from time to time and everything will feel very bleak and impossible. Be kind to yourself.