This could just be my own opinion, but maybe you need a break from thinking about it.
Nobody says that it has to go either way - you follow through or give it up.
Give it some time when it's not gonna be on your mind. Let yourself live a little.
Right now your feelings are holding you back and playing with your mind.
Take some breathing room, just enjoying some music, a walk with some friends, etc..
Sounds like your still young, and shouldn't have to face all this drama right now.
Relationships are a great thing, but it doesn't have to be the center of your life just yet.
You're still in touch with him right? Maybe that's one of the issues...
Maybe if you're not buggin' out over each other things will simmer down and get back to a good relationship. I don't think it would hurt him (depending how you go about it.)
But the same way that you don't like hurting others - don't let yourself be hurt!
If you don't think that in your situation this idea will work, feel free to say so...
maybe trying to work things out is a good idea. I've got experience in that direction as well.