When you have insomnia, a lot of times it's from your mind racing. If you have something going on in your life, or have to be up early the next day it can cause your mind to race, causing insomnia. What you have to do is stop thinking, clear your mind and say sleep, sleep in your mind over and over. Someone told me this worked for them for insomnia.
There are several over the counter things you can purchase that helps you sleep without waking up feeling drugged up. Primrose oil helps me, I take it every night.