Ditch the person right away. There is no excuse for him (or her) to hit/slap/grab/shake you-- ever. If you were playing around wrestling and it happened accidentally, that's understandable. If he (or she) got too angry and lost control, that's not. There is no reason to ever be with anyone who hurts you.

Sometimes people think, "Well, he (or she) loves me, and he/she's one of the few who does, so it's ok." It's not. If he or she is physically abusive, he/she doesn't love you. That hurts more, but hopefully through that pain you realize you must get away. Nothing good comes out of abusive relationships-- except you, if you get out.

It's very scary to leave someone, especially because you'll feel totally alone. Abusive people intentionally make you feel worthless without them. Don't believe the lies. Trust yourself. Believe you're a good person-- you are-- and trust you can find real love which doesn't hurt. You can.

There's someone nice for everybody. But the only way to find that good person later is to get out of your bad situation now.