The thing is that a lot of players are goodlooking, funny and charming. They use this to draw people in and then when they are fed up or bored, they just reel in someone new.
I think a lot of players have a moment or two where they regret the way they are and wish they could have a stable relationship. They are honest about the way they behave and say - quite truthfully at that point - that they wish they could change.
HOWEVER, whether it's due to a weakness in character or what, they always, always revert to type.
Now this man told you what he's like, and because you were charmed by him, your mind couldn't accept that actually he was telling the truth. You thought that charm was just for you - it's intoxicating being drawn in by men like this. But they use this charm on everyone - just notice how often he turns it on, especially if he's done something wrong. I bet there are police officers on here who could say these guys will always have a winning smile and a quick joke, a compliment or two, to try to get out of the fact they've driven badly or parked illegally. It's what they do - they would have been charming babies, children, young men. It's how they get what they want.
You need to treat this man as though he's an addictive substance - you are addicted to him. You know he's bad for you - he's like the notice on a cigarette box which says it will kill. He's told you as clearly as that that he will hurt you - not intentionally, maybe, but you will get badly hurt if you carry on seeing him.
And as for his manhandling his previous girlfriend - god, OP, he's actually told you that. Take it as a warning.