Abuse. I really need help.

I really Need your girls help. I feel like I can't tell anyone about this and it's tearing me up. I'm pretty sure I'm in an abusive relationship, sorta. It's not a relationship, just a fuckbuddy. But it's emotionally, and physically damaging and idk how to quit him, cause I have feelings for him. He was my first one, and has been happening steadily since the first time. At least once a month. But the last few months he's been happening weekly. And it wasn't too bad apart from him slapping my ass a lot and biting me, but who doesn't like a little of that stuff? But tonight was when shit hit the fan... He tried to go up my bum.. And I said no and how it was uncomfortable but he kept trying, so I said my usual "consent is key" and he ignored it and kept trying so I said how if he kept trying that that was how he gets charged with rape. He got all pissy and mad and just stopped completely and I feel really guilty and idk why I feel this way. Even as I type all this out I can't stop crying. I know what to do, but I'm just not strong enough to do it. It's tearing me up on the inside because I really do like him and he's not a terrible person but I just can't deal with him having no respect for me. I know you all are going to say that I need to drop him, but I don't think I'm strong enough to. I just can't.. It doesn't make it any better that I consider him to be one of my best guy friends. And even now as I continue typing I feel guilty for saying the whole rape bit to him.. I know I shouldn't but I do.. He's really fucked up my mind and idk what a healthy relationship is anymore. I really just need help, but I can't reach out to my friends cause no one knows about us, plus they all see him as an angel..