Dude, relax. Stop falling in love with every other girl you see.
You see school girls are simple creatures. Usually pretty shallow and not worth getting too worked up about. It would, however be a good time to get your confidence up and learn some GAME. You have any game? Doesn't sound like it.
Take care of yourself. Work out, dress nicely, do something you're good at. Above all, do YOUR thing. Live your life for you right now, and if a girl likes you for who and what you are, then maybe she's worth your time.
In the meantime, chat them up now and then. Don't ask them out or try and see if they like you, just be friends. You need to learn how to talk to them. Be friends, but DO NOT GET FRIENDZONED. Friend zone = hell.
Be glad you woke up when you're young.