Tell a friend, get them to tell the police if you can't do it yourself. They will want to talk to you- but a friend will do the initial step to talk to the police.
I know its probably really hard for you, but you really do need to do something hun... It's not right that you have to go through the worry everyday, you most probably don't deserve it at all. Think about how much of a weight will be lifted off of your shoulders once you've told someone, and the guy is locked up.
And think of it this way: It wont be you that your just helping by telling. You don't know how many other people he's done it to, or how many more he could do it to. Save others the pain too... Tell someone.
xXx