A kiss? And then he THREW ME?!...Help!!?

This is really detailed, therefore, it must be really shocking for you (hard to forget). First off, do you actually love him? If not, then the kiss would have been meaningless. If you had no feelings for him, but he had feelings for you, an empty kiss would have been heart-breaking. If you two were especially close, you would not hesitate to get him back. Now is not the time to be stubborn. If he was really important to you and you know that you were important to him, clear things up. Make sure that he knows whether you really liked him or if you just felt comfortable giving your first kiss to him. Tell him that you were hurt physically and emotionally. If he denies you friendship, then it's done. You have your closure, and the knowledge that you were taken kicking and screaming (you did not give up). This will take a lot more courage than it sounds like.And don't forget that is you hadn't slapped him, he probably wouldn't have hurt you(male strength is really different from female strength, so he might have accidentally don overkill. If he hurts you again, have the courage to tell a trusted adult. I hope this really helps!