my bf raped someone

i just need to tell someone because it’s making me physically sick. not telling anyone. keeping it to myself when i don’t want to. it was some big party and i went with my boyfriend of almost a year, i got pretty drunk and i’m not one of those girls who stick by their boyfriends side i wandered off and hung out with my friends but i went upstairs to pee and then i got nosy and wanted to look in peoples bedrooms. i walked into a bedroom i saw him raping someone. i don’t want to go into details but he was on her and she was lying there and she looked dead and she was face down on the floor. i didn’t think i just ran over and pulled him off or tried at least he’s really strong but he saw me and he freaked out and he got off her and i ignored him and went to shake the girl to make sure she was alright but he fixed himself?? and grabbed my arm really hard and dragged me out the room. idk it didn’t occur to me to scream but he pushed me back into the bathroom and he tried to play the ‘i’m sorry for cheating’ fuck that it was not cheating it was RAPING and i told him that and then he tried to gaslight me but i wasn’t fucking buying it i’m not an idiot i know what rape is and then he told me just a bunch of stuff. threats and reasons i need to shut up. i’m not going to air my stuff out but he knows things about me i don’t want out and he mentioned them. and then he just kissed me and walked out????? i was going to do the right thing here and i was going to risk it and tell someone but when i went to check on the girl she made me fucking swear not to tell anyone. like she was furious and she told me if i told anyone and i made it seem like he’d done anything she would never forgive me and she’d hate me. how the fuck does that make sense? but i listened. and its killing me. i can’t break up with him. i have NO reason to other than he’s a rapist. if i break up with him he’s going to spread all shit about me and i can’t even back myself up because he’s gonna call me a liar and that girl is going to call me one aswell. so then im a girl who lies as well as the other shit. he doesn’t try and touch me though. in public just a hug or a hand hold that’s it and then we don’t hang out one on one anymore. he’s tried to. get my forgiveness and tell me there’s something wrong with him and he’s going to fix it and he’ll go therapy and all this shit. he’s really good at lying and manipulating and whatever the fuck. sometimes i want to just say okay and be normal. it sounds bad but it’s true. how can i be mad when the girl he raped isn’t? sometimes i convince myself he didn’t rape her. she was mad and told me to shut up because she knew she wanted it and it wasn’t rape. i was drunk and confused. but i’m not i just know in the way i think girls know?? i’m sick all the time. like i throw up every morning, im constantly nauseous. anytime he touches me i have to try not flinch and then sometimes when he buys me flowers i like him for a moment and then i honestly want to die for being so weak. i’m in mental warfare. and she isn’t saying anything. and he’s gotten away with it. or he’s going to crack me. he’s going to break me and i’m going to have some breakdown and force myself to get over it. or he’ll rape me. or someone else. and then i’ll kill my self. and if people do respond to this. dont tell me to dump him. can you please just fucking trust that i can’t?? i can’t. not unless that girl talks. and i can’t talk if she won’t. i know that’s wrong. and since this is a confession and i can say what i want…i hate her. and i hate her for doing this to me.