How to maintain a good sleep?

I'm having trouble with sleeping. I also struggle to fall asleep and wjen i do it gets late already and i have college the next day. Once i even have stayed up until 6 am and didn't sleep...not even a wink. I told my mom about it she accused me that i have thoughts though i don't i explained to her that i don't but she doesn't believe me. I remember ever since i was a kid i struggle to fall asleep and a war happens between me and my parents because of that. Even the time i fall asleep, i wake up later and i try to put myself back to sleep which takes a little time to work. I can't afford going to the doctor about this and i don't want to be put on sleeping pills I'm still too young for that...I'm only 19. Time doesn't matter even if i go to bed early I'd stay up until the time pass to a late timing. The thing is whenever i go to bed even if i feel tired i get suddenly alert and hyper. I really don't know what to do I'm starting to get daily headaches and it's not healing with painkillers. Any idea what i do in this matter? I'm really tired from this.

I don't know if ADHD is still a factor because i was diagnosed with it as a kid and some symptoms has decreased so much. So idk if this is still related.

Can you please help me?