Ugh. Help.

My emotionally abusive ex keeps coming back. We broke up. And then he came back after about a month saying sorry and that he wants me back. I gave him another chance which lasted about a week before breaking up again. He's really rude to me. He calls me names like "whore, bitch" and says rude comments like how I'm looser than blah blah. We used to break up a lot in the first bit of our relationship but it usually only lasted for a few hours. He treated me like shit starting at about half a year. But of course I loved him and was blinded by it. He owes me a lot of money now. And I'm
​Just confused on why he still feels the need to hurt me when we're not even together. Like obviously he's flirting with girls and shit now because he tried to hurt me since we just broke up again. But the thing is I don't really care. That was an emotionally and mentally abusive year and a half with him and I just don't know what to do.