When I was at University I found that I had the same problem.
What worked for me is very similar to a couple of suggestions that involve meditation/breathing.
1) Sit on the floor in a kneeling position.
e.g.
2) Breath in deeply, as you breath in lift your arms in a circle in front of you (close to your body so they cross).
3) Breath out deeply, as you breath out, lower your arms in a circle on either side of your body. The arm movements may sound silly, but they help your diapragm in making a deep breath.
4) repeat 4-5 times. While doing this do not think about anything else.
5) After doing the breathing exercise, your body should have slowed down. Go to bed and banish any thoughts that enter your head. If you have to think of anything just focus on breathing slowly.
After 2-3 months, I did not have to do the exercises anymore, and best of all, I did not need any drugs or therapy.