My boyfriend is being agressive towards me?

we were play fighting then he got serious and raised his fist getting ready to punch then apologized later that night. That was the first sign of agression. Two days after he randomly started verbally abusing me calling me a slut,***** saying that I sleep around and I don't deserve him etc. then he apologized again and like an idiot I forgave him straight away. I found out by the horses yesterday crying and when I tried to help he told me to **** off. There is something wrong with him and I can't get it out of him. If he doen't fess up to what is happening and fix his behaviour should I leave him?