He does not love you.I'm sorry but no man who loves a woman will hit her.And what you said about him not wanting to see you get hurt,how can you think that he doesn't want to see you get hurt if he is hurting you?
I have been in your situation before and I know all the things you will tell yourself to make it seem right in your own head,but sweetie,it's NOT right.
Anybody who would lay their hands on somebody that they claim to love is a liar.
And about all his ex-gf's being liars and abusive,have you met them? If not than how do you know that it isn't your bf who was the liar and the abusive one?He's abusing you now,what makes you think you're the first?
I know all this sounds harsh but it's called reality and you need to re-evaluate your relationship and get help.I'm not going to tell you to leave him,because I am not you.Only you can dictate what YOU do.
I think you and your bf need to get some counselling,try to work past your issues.