Issues with a guy

Some of you will probably think I'm stupid for being in this situation, I know I do haha.

But there's this guy I've been on and off with for a while and I'm just at a loss of what to do. He's just so hot and cold. One day he tells me I'm perfect for him and he doesn't want to be with anyone else and then he ignores me for days on end. And out of no where he'll call himself my boyfriend but then go back to ignoring me. The other day he was telling me all these sweet things and how much he loves me and like an idiot, I thought he meant it. I thought we finally got back together and I slept with him. But the very next day he backtrack and said we're "just friends" and that it was my fault for reading into things too much.

But... That's not the only problem. He's always been one to rough house and play fight but the past month or so he's... Gotten a bit mean with it. Like, I'm staring to think he's hurting me on purpose because I'll tell him he's hurting me or shout in pain or beg him to stop and he just doesn't. He usually just says I'm "being a baby" or "too sensitive" but it's not uncommon of him to leave marks. My roommate started getting suspicious of me wearing long sleeves and hoodies to hide the welts and stuff because I don't want her getting the wrong idea. But I feel like an idiot because I'm still defending him, reminding others that he's just playing and wouldn't actually hurt me. Hell, he does all of this in front of his friends and they don't think anything of it- so maybe if nobody is speaking out I'm just being dramatic? I mean, he's just messing around. It's not like he's hitting me because he's mad or something. I'm just confused because he doesn't really do this to anyone else and with everyone else he's usually pretty good with boundaries and such.

I'm just at a loss. Being with him hurts me but being away from him hurts, too. I just feel so defeated. No matter what I do it always seems to be the wrong answer. I stood up for myself yesterday and told him we shouldn't talk for a while, but I want nothing more than to run back to him. I'm going to try and avoid him for a bit, I know I can't trust myself with him.

I'm not sure what I expect from this or why I'm even posting, probably just to rant since I don't have people to talk to I guess. Any advice or words or encouragement or whatever would be nice.