My boyfriend and I had a fight two nights ago...?

We've been going out for a year and a 1/2 and are in our mid-twenties. We both got really drunk after the bar and started play fighting. Apparently he was getting really upset and he threw me off the bed really hard and I landed on the floor on my head and then he left the room. I got up and punched him in the upper body and face about 4 times. I didn't put all my effort into it I just kinda lobbed them off and his lip started bleeding. I know I shouldn't have hit him, I'm well aware of that. I believe we're both in the wrong for being violent. He broke up with me for that. But I really don't think It's entirely my fault. I'm not a violent person, but I can't stand when a man physically abuses a woman. We're really close and I just am not sure if it warranted him breaking up with me....