mom putting her boyfriend before me, her daughter?

my mom has been with her boyfriend for basically my whole life, (i’m 15 now) when i was around 7-12 it was really rocky between us like when my mom wasn’t home all we’d do is argue , and i’m not gonna lie i definitely had anger issues back then but he brought it out of me. sometimes my mom would be yelling at me and he’d be behind her making faces just to egg me on, once we were in the car (me, him, and my mom) arguing and he grabbed the book from my hands and ripped the pages out and threw it in the trunk, once my mom and i were leaving the apartment we lived in at the time because they were arguing and he said “if you don’t get back inside i’m going to burn this whole complex down” which i swear he said but both him and mon deny it to this day, but it’s a pretty vivid memory to me. once me and him were in the car and he was yelling at me and slamming on the roof of his car, then afterwards told me not to tell my mom because it would ruin her day. i told my father about all of this, and in this situation she thought i was lying because she said that i took so long to say anything. my dad definitely had concerns and her email back to him was basically “he’s a big cuddly bear he wouldn’t hurt anyone” meanwhile when we’d be home alone if we’d argue he’d throw cords, slam doors (which is pretty normal), and scream. in the moment i guess my mom would defend me sometimes but when we talk about it now she kind of blames me. i was talking about it to her a couple of months ago and i kinda questioned why she didn’t break up with him, and she told me she did many times but i’d want him to come back. i remember doing this once. and that’s because i thought it was my fault and i hated seeing my mom so upset without him there. anyways he’s left a couple times and he’s bipolar, so he’s on meds and he’s not like that anymore. sometimes i see the way he treats my mom and i don’t like it, i don’t say anything though. i hardly spend time with him because if he’s home i just isolate myself in my room, it’s really hard for me to be nice to him nowadays and i don’t know why, maybe it’s because of this stuff in the past and the way he treats my mom but i just can’t do it. so i rather just stay in bed all day than be cold to someone who’s trying to be nice. anyways over the summertime he was taking me to hang out with a boy, and he was giving me this talk about boys and then goes “you’re hotter than hot” which really made me feel uncomfortable and i never told my mom he said this. the. one day he was talking about how me and my mom are the same about wearing short shorts, which also made me a bit uncomfortable because i don’t like the thought of him looking at me like that. idk if it’s just me. he’s always kind of given me the creeps, like he treats and acts like he’s in love with me sometimes and it’s gross to me. he’s gross to me. so i finally told my mom this tonight and she was like “i don’t think he meant it in that way” which i thought too but i just don’t understand why she’d say it. and she knows i can’t stand to be around him and now she knows he makes me hella uncomfortable and to this day she stays. which i never asked her to leave but she was like “you know i have a life outside of you” which i understand but if I had a kid that means Id make decisions based off of them and they basically would be my life. i just can’t live a happy life living with him. and i told her it’s never worked out for years and i just don’t think it’s going to and she went “that’s life” like she doesn’t care at all. and when i told her he made me uncomfortable, and when i was on vacation i didn’t want to be in a bathing suit near him she went “well you know he’d never do anything like that towards you” which i don’t think he would but the problem is you never know. you can’t say you know for sure someone isn’t gonna do something like that for sure. anyways that does anybody else see this whole thing as a problem or is it just me overreacting?