@ Kaliope: I have the same exact sleep problems that you do! I've been an insomniac since I started puberty, caffeine hypersensitive (I actually twitch so much when I OD on it that it looks like a seizure!), & now I need around 10 hours of sleep before I feel "well rested". I did more research & I attribute the insomnia & oversleeping to a disorder called 'Non 24 hour circadian cycle' where you need more hours of awake time & more hours of sleep time because your circadian rhythm is naturally different. It interferes a lot with schedules such as school/work/etc.

@ Moonbeam: Yeah, that is a 'early waking' disorder associated usually with depressive problems. I hope you can find something to help you sleep though!! Good luck to you.