HELP ASAP!

Dakota

Okay ladies so I need help and I need ASAP!! I just moved into my apartment tonight with my female friend/roommate (lets call her M). So M just recently (within the last month) started talking to this guy (let's call him P). P was my first boyfriend (I was 12 now 18) and shortly after P and I broke up he raped me. P was 13 and biked 10 miles in the middle of the night, climbed in my window, and raped me. Yes I know it's been 5-6 years since the incident but I still have severe mental issues when seeing or talking to/about him. I haven't seen or talked to him much since the rape incident and I'd like to keep it that way. Tonight is mine and M's first night in our new apartment and P is over just casually sitting in our living room like never ever happened between us. M knows every detail about what he did and how he did and still does make me feel but refuses to make him leave and insists that he's changed and it's not my place "to decide her relationship for her." I don't know what to do. I'm honestly scared out of mind and don't know who to turn to. P is the reason I started cutting/attempting suicide in the first place and I've just started getting to a good mental state. I don't want to revert back after all this time of trying to get better. SOMEONE PLEASE TELL ME WHAT TO DO?!?!?!!!