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)