Lately, I've been having the same problem, but I do have a suggestion. If you can't fall asleep~ and it's late, just start thinking about something. Do you have a crush? When I couldn't fall asleep~ I always used to think about Nick Jonas, and make up stories (of how I could meet him and stuff). I don't do that as much anymore, but I think it's a good way to fall asleep. Another thing, is to think of stories about you and your best friends, and try to do that too. I do that now, more than think about my crush! LOL! Well, there ya go, I hope that helps a little bit.
Hopefully tonight you'll be able to get to sleep!
Happy sleeping,