It's perfectly normal. Try exercising in the nights it will get you exhausted and at least you go to sleep. Don't be a shame of your sexuality
Why Can't I Stop Thinking About Sex?
Get your mind off sex and relax... You do have friends right?!? Talk to them to see what they are up to? maybe go hang out and get out of the house!
Do something with grabs your attention... Like spend time with your friends.. At that time... Don't try to stop it.. If so.. It will always grow ..... It is your teenage.... So it is not wrong thinking about that... But play games.....