I can't sleep well at night(18YO)?

It's been 3 month since I can't sleep properly.I go to bed at 12:30 or 1AM and just can't go to sleep until 3 or 4AM for no reason.I really need at least 8 hour sleep to recover because I workout a lot.I take some supplements to improve my workout performance such as a pre workout pump which has some caffeine in it but I only use it before my workout.Is it possible that caffeine stays in blood for long hours?