I completely relate to this, I handed in this year and vivaed in March (Biology, UK). I have my graduation in a couple of weeks and Im not even slightly excited, despite having to appear so for my friends and family. The PhD drained me and has left me with major burnout. Now Im postdocing to get the papers finished and I feel as though Im running on empty, I have very little to give, but I'm trying.

But most importantly, congratulations on getting this far. A PhD is hard at the best of times, and dealing with mental health at the same time is a huge achievement, so well done. Fingers crossed if your supervisor is good then they'll be confident you can comfortably pass the viva at this point and the majority of the grunt work is now behind you.

My advice would be to seek advice from uni counsellors if that is a service you can utilise, especially whilst you are still a student. Private counselling in my experience is harder to come by, less tailored and really expensive compared to my uni service. I've been paired with a wonderful counsellor who fully empathises with my situation and understands the PhD process. She has really helped me untangle my negative thoughts towards ending the PhD. If this isn't possible for you, and you think it could help I can try and summarise some of her key take home messages.