I want to get better sleep but can not maintain a proper schedule due to university, 2 days a week it's waking up at 8 AM and otherwise 10 AM/11 AM.
I usually have coffee at Morning and a light coffee at 5 PM, it generally helps to do more work because I feel like I want to sit and work. Otherwise I'd dopamine max or play a sport.
Any tips on improving sleep? (It's simply not possible to follow a strict schedule due to multiple deadlines of so many things)
Is there actually a good reason to be sleeping at 3-5am? You'll probably notice significant improvement in all areas of your life if you sleep at something like 10pm EVERY day and wake up at 7am. And get rid of coffee, and exercise regularly.
As the others have commented, wake up at the same time every day. It's really important. It will help. It will take weeks or months to help, don't decide it's not working after a few days.