Maybe you're too stressed out to fall asleep. When I'm stressed, I always find it even harder than usual to sleep. Try reading a nice book while drinking chamomile tea, that usually helps me. When that doesn't work, I take a melatonin pill. (mine dissolve quickly and taste like minty chocolate!) You might also want to see a doctor, he or she might have some ideas as to why you're having trouble sleeping. don't worry though, they don't always give you sleeping pills, most doctors try to find alternatives before prescribing sleeping pills. Good Luck!
Everybodies body clocks are different so if you find your not actually going to sleep when you go to bed, then it's probably not time to sleep. At some stage of the night you will find that your body will become weary and want to rest and you will fall asleep much easier. A few tips though, darkness promotes the hormone/endorphin that makes you tired so turn off the lights. Avoid caffeinated substances within 2-3 hours before you go to bed. Lastly, counting sheep actually works especially if you visualise them walking past or appearing (i picture mine jumping over a fence) I never count much past 100 if i'm lying there in the dark with my eyes closed. Hope this helps
If you have a phone with apps, go to free apps. They have sleep and relaxation apps like Banzai, etc. I sleep like a baby with The Sleep Machine app for free on my I phone . Just use your headphones with your phone in bed and you will fall asleep guaranteed!
I had a wonderful young woman tell me one time that the best way to rest well is to close your eyes, and go to a place in your mind of the best memorys you have. She said if you can go to that place of peace and happy memorys, and have a little grin on your face, and a smile in your eyes, you will have peaceful dreams. She was right. Just grin, smile in your eyes, and recall the best of times as you fall to sleep.. goodluck.