Wether painful or not, the simple act of hitting a woman is abhorrent, disgraceful, distasteful and extremely cruel.
He is nothing else than a bully and not worth your time or affection.
Just like other members have suggested, I would recommend you to dump him, as the next time he beats you, it could be very paiful, or may even kill you.
The ball is in your court, nobody can make the decisions for you but yourself......