my sleep schedule is so bad

ive been struggling to sleep every single night, i have no problem with staying asleep but i just cannot get to sleep even when im like sooo tired i physically cant sleep and when i do its always between like 10am-3pm. some days ill stay up for like 1-2 days and go to sleep at a decent time but then i always wake up early asf and ill have a nap during the day then my sleep schedule is messed up again. melatonin doesnt work for me and i do not wanna go to a doctor bc that just seems unreasonable. any solutions??