- Maintain a routine (lack of sleep / too much sleep) can often make you feel even worse.
- Get up and go to bed at set times, allocate time for leisure (I get this is difficult given the current exam period but "time to unwind" is absolutely critical for the mind.. and no, a job is not "leisure time").
- Eat properly - breakfast/lunch/dinner at least. Snacking in between too.
I know this is a very casual attitude - but your focus realistically should be on consolidation and review, rather than any sort of additional learning. My approach to things just before an exam "if I don't know it by now, I probably never will". Whether you accept that advice or not, I think the main message i'm trying to get across is you shouldn't be running around crazy at this point. Make time for a break, eat/sleep well and all will come together. Your mental state is EXTREMELY IMPORTANT... and should be your number one priority.