Year four of the PhD and I can't open my own thesis file. Has anyone come back from this? Study & PhD

Yes, and the first week back was not writing. It was twenty minutes a day of touching the file with no requirement to add anything at all — open it, read one line, close it, walk away. Nine days of that before I wrote a sentence. The sick feeling is a conditioned response to the file, and you have to break the association before you can ask the file for work. Writing through it just teaches your body that opening the document is followed by an hour of misery, which is exactly what you've been training for five months.

Tell your supervisor. I know. I said 'it's going fine' for eight months, and the conversation I was terrified of took eleven minutes and ended with a restructured plan and a monthly deadline. Supervisors have seen this many times. The version they haven't seen is the student who says nothing until the funding runs out, and that's the one that ends badly.

Find out what your institution actually has: many run a formal interruption or extension route for health reasons, and some have hardship funding. It's usually badly advertised and involves an unpleasant form. Ask the postgraduate office directly rather than guessing from the website, and ask early, because these things tend to have deadlines much earlier than you'd assume.

Write the worst possible version. Genuinely bad, in a separate file called rubbish.docx, no citations, sentences like 'then we did the thing and it was weird'. Every decent chapter I have was once that file. The sick feeling attaches to producing something that will be judged, and nothing in rubbish.docx will ever be judged by anybody.

Seven months of funding is a lot more time than it feels like right now. I wrote 60% of mine in the final nine weeks after five months of nothing. I don't recommend that route, but it is evidence that the state you're in is not the state you'll be in.

Boring body stuff: I could not write until I fixed sleep, and I could not fix sleep while going to bed at 2am feeling guilty about not writing. Breaking that loop took a fixed bedtime I kept even on days I'd done nothing. It felt like giving up. It was the thing that let me start.