One tip which I didn't see: set an alarm for going to bed , not waking up . You should be able to wake naturally, but artificial lighting changes your perception of when you should go to sleep, shifting you from a naturally 23-hour circadian rhythm to a 25-hour one. So just set an alarm for 11pm, and when you hear it, immediately stop what you're doing, save any open documents, turn the TV or computer off. The next 3…
You're clearly not a student :). I'd love to choose when to go to bed, but that's not really compatible with a workload challenging enough to appease admissions counselors.
Use time-boxing as a scheduling mechanism. If you find you have more work to do than time to do it, start lopping off items from your to-do list, and/or identifying how you can accomplish a sufficient effort in the time available.
That is likely to be a far more useful life lesson than whatever subject it is you're studying at the moment.
You also have to learn how to schedule downtime. People cannot run 100% 24/7/365, and attempting to do this is at best very painful, and at worst, literally, suicidal.