I may have something for you... I used to have the same problem, caused by my horrible habit of procrastination. I would put off everything until way late and then do it all even later and get three hours of sleep a night and be dead in class. Then I found my new schedule, outlined below. However, it requires that you have no life outside of school and that you have parents who don't mind your doing it.

My schedule:
7 a.m. -- Get ready for school.
8 a.m. - 4 p.m. -- School.
5 p.m. - 2 a.m. -- Sleep. This allows me to get 8-10 hours of sleep per day and I don't need to set an alarm. I love being able to wake up when I feel like it.
2 a.m. - 7 a.m. -- Do work. If there's nothing to do, goof off until 7 a.m. Also, I technically get to stay up late, which I love to do.

I will say that I have to break off of this when there is a paper or other large assignment due and it's still sketchy on weekends. However, it has never failed me on weekdays and I've gotten as much as eleven hours of sleep on a school night (5 p.m. to 4 a.m.). So if you're so inclined, I've found that a change of schedule can work wonders.