So called "stepdad" is too much to deal with

well where do I start… my mum is married to the the biggest jerk on the planet and hes using her and just about any other woman he can get his filthy hands on she doesnt believe me tho and doesnt even hear me out he uses her for sex, for her to clean his clothes for him, cook for him, her good english.(because he’s an imigrant from albania) and he also has a another woman on the side that he uses for money because my mum dont have much money he’s like a male prostitute. he gives the other woman sex and gets some of her money in return. only he’s lying to the other woman. hes saying he loves her too and my mum knows about the other woman too btw but isnt stopping it because she doesnt want to lose him tho he’s never once shown his love for my mum whenever I say how hes using her, her response is “how wud you know, you dont know what goes on in our bedroom” but like sex doesnt mean you love someone!!! he just gets all the pleasure from it doesnt mean he loves my mum and he also tried to kiss me and he put his tongue in my mouth when I was 10 years old, he was drunk and he probably wud have raped me if I didnt scream my family were in the house but my room is way at the back of the house so they probably wudnt have noticed anyway when I tell my mum this she never believes me and just says “your lying because you want me to divorce him” it really hurts that she doesnt believe her own daughter over that a$$hole and any money he does get he never gives to my mum my mum and I have never had a happy stable life and I think she deserves someone who will truly love her and provide for us but he’s doing jack sh!t for us my mum also found cocaine in his jacket pocket one time and just said “oh it doesnt mean anything hes probably just selling it” like what THE FxxK?! SELLING IT IS OK?! im sick of all this I really dont know what to do

and im scared that when I leave and get married and stuff my mum will have no one with her to love her and he may also abuse her by raping her and/or beating her he has beaten my mum before and I just dont know what to do about it oh yeah and I cant even call the police because she said she’ll disown me if I do it

PLEASE SOMEONE HELP ME =[