Am I in the wrong?

Me and my boyfriend were arguing and he ended up poking me in the face, he then wouldn't stop shoving me around the house and wouldn't move out of my way. Every time I tried to get past him he would push me. So I slapped him in the face and my ring scratched him and left a mark.

He says i was in the wrong because I slapped him, i didn't think I was wrong at first because I've asked him to stop pushing me around when we argue and he didnt listen, but now I'm not sure who was initially wrong