I agree with some of the above, especially the part with sleeping when you feel like sleeping, don't make it forceful and exercise during the day. Do you use your sleeping area [bed, perhaps] for things other than sleep? If so, don't.. you want your mind to identify the bed as a place to sleep. I remember in psychology class, something about getting up from bed if you can't fall alseep within 30 minutes..get up and do something mellow, and maybe you'll fall asleep after that. Wake up early and don't sleep in.. I hope this helps, I generally don't sleep until 2-3 am but lately I've been doing some of the above and this week, I've been crashing at like midnight.
