You are so young to be having this peoblem! Just a question, do you drink a lot of soda or regular tea, iced tea?
Those drinks have a lot of caffine in them and most regular teas have more caffine than coffee!
Your obsessive activity is prob from the expectancy that you aren't going to sleep and the frustration of waiting for sleep to happen...In short it is probably due in part to anxiety.
Did your doctor run any tests to see why you are having these problems?
It sounds like you need to go to a specialist to determine the cause.
Over the counter meds are fine for an occasional problem but not a long term cure! You are young and if you are a girl you must consider any damage to your reproductive organs, liver & kidneys of any long term medications.
Have you been checked for sleep apnea? Do you snore? Do you have pain? What kinds of things do you think about when you are trying to fall asleep? Do you worry about things that are going on rather than trying to clear your mind?
A simple trick to try is to eat some protein before going to bed, something like a piece of meat or a spoonful of peanut better just might help. Don't make it a sandwich, just the plain meat {poultry is a good choice, and not processed deli meat but the real thing} or a spoonful of pb.
You can also try "imaging" as you try to fall asleep; just imagine a special world where you would like to live, your own planet, a town, etc. And imagine what kind of house you would have there---your own design, your own colors, your own furniture, maybe all futuristic, imagine the sky of your world, maybe 2 suns, a garden, what kind of flowers, etc. It just gives your mind a chance to relax and explore and gives you peaceful things to think about.
Hope I have helped a little!