Sleepless nights

Does anyone knows how to cure short term insomnia?
I CAN'T SLEEP LATELY! As always,I'll suffer from insomnia on exam periods and this is annoying.When I closed my eyes, my mind never stop functioning.Many many things go through my mind;I just couldn't get into my dreams. I did do some researches with regard to curing of sleeping disorder and tried several methods(drinking warm milk before going to bed, listening to smooth music, doing exercises in the morning and breathe slowly) but to no avail. If only the worst comes to the worst, I will consume some sleeping pills as given by a doctor.I know I cannot rely on sleeping pills but what to do?

Last night, I didn't get a wink of sleep. Only till this morning around 7am when my sister prepared herself to school, I fell into my dreams like finally but a short one. I woke up at 10am as I had a paper at 2.30pm. Gosh.I had only 3 hours of sleep or even less than that!! Apparently, I didn't do well for the paper even though I was well prepared.Most of my answers were different from my class. Ah~
Sigh.It's over though. I had done my very best for this paper.Hope my results will turn out to be good. * Keeping my fingers crossed.

Alright, shall prepare for last paper tmr!!