@Definitely..maybe I very much understand. I did my BA and Post - grad while very unwell. I think I did learn a few tricks ;)
1. Learn when your energy levels are better and worse - arrange studying around that. So if you find mornings worse - do less intensive things then...
2. Plan your work - broadly by week and then by day - but plan rests and breaks and days off!
3. Work for no longer that 50 mins - 50 working - 10 break - 50 working - 30 break - 50 working - 10 break - 50 working - long break/stop altogether (or something like that.
4. study using different methods - reading/note taking, brainstorming, listening to audiobooks, podcasts, record lectures, if you are too tired/spaced out to study, spend some time organising your notes.
5. Don't get overwhelmed my "blank page syndrome" - Write something! Anything! It is much easier to edit afterwards - never delete anything - you can copy and paste material you think is not good onto another document - but don't delete it!
6. Have a morning routine (ha! I know!) Eat regularly, try to get some sleep, go for a walk etc.
7. Plan your next day before you go to bed.
8. Grounding - try to find things that ground you - I make playlists that help - sometimes I used to make one for "tomorrow" and have one for each day of the week, simple mobile phone games to play in your breaks- repetitive ones that can help clear your brain.
9. Talk with your lecturers about what things you can miss out! Don't try and do everything!
10. Try and find small things that you find comforting to put into your day and evenings- comfy slippers and clothes, music, hot chocolate, tea, snacks, seeing kind friends, afternoon naps, going for a run, long baths, nice hand cream - whatever you like :)
11. Take all support you can get!
12. Just keep at it! Keep going and don't focus on bad days - you will have them - In the words of a wise fish just "keep swimming" :)
Hope this helps!