I cannot sleep! help?!

I cannot sleep! help?

I have an exam tomorrow, and one that would need lots of mental energy. But i cannot sleep, and this is not the first time that this happens to me. Its 2am and i hav to wake up by 5.30am tomorrow. When i try to sleep my heart beats really fast cuz i am nervous. Can anyone give suggestions? Or anything. Normally i sleep within 5min but i am nervous thats why. Yet this is not the first time i cannot sleep b4 exams

Go to the grocery store pick up a box of Sleepytime tea.... In the coffee isle.
Make a hot cup of tea using 2 tea bags. Add a little honey or sugar if you like. It is a mint flavored tea good for toddlers too. Within a half an hour you will be ready to get a good nights sleep. WITHOUT waking up feeling sleepy!
And the best thing is, it is not a medication!