How to tell this b**** that he's my guy.??!!?

First off it's not your boyfriends fault, so everyone BLaming him below should shut up. Secondly, you need to tell your parents. Trust me, you have more than enough drama right now. Those are serious threats not to be taken lightly. You have done nothing wrong, you've been threatened and your scared. Let the adults do the rest before something really bad happens. And trust me, a rumor about your bf and her having sex will be the least if your worries if this continues.