Violence

Didn't know which group to put this in but I reckoned this one was the best one because people have so many different views on this subject. 
I've been with my boyfriend for a year and a half now. It's great when it's good. When it's bad it's terrible. When we fight we get into physical fights. He's bigger than me and when he hits me it really hurts and I can only try and defend myself by covering my head and stuff. Also when it's bad he has a seriously crazy mouth! He can say the most awful things to me. Saying he will send around nudes I have sent him and stuff just to make me listen to him.
I dunno? Do u think this is ok. This doesn't happen all the time and not every argument involves physical force. I've considered leaving this relationship before but I haven't because I love this guy to death. What do you think I should do? What should he do? Has anyone else been through this?
Please don't tell me if he really loved you he wouldn't do this because that's bullshit and doesn't help me. I know he loves me. If I ever doubted it I wouldn't be with him. 
Thank you for the advice x