Telling mother I don’t want to be like her?

Mean I know. My mom and I don’t have a “relationship”, she’s toxic and has made fun of me physically which led to an eating disorder and so on. My mother got into a relationship with a man 4 years ago and in the beginning it was whatever like she’s happy good for her but not too long ago I overheard her talk about how he doesn’t help her financially and how she pays all the rent meanwhile he don’t pay SH*T when he makes so much more than her. That obviously bothered me because like mom really? Open your mouth and f*cking say something!!!! He also cheated on her in the past and she stayed. It’s frustrating because I thought she’d know better, I also have a little sister and brother and they know about it and I don’t want them growing up that that’s okay because it’s not. Yesterday I visited my mom from out of town and slept over and I was in the kitchen with my brother talking about how his online schooling is difficult for him and I was also cooking my moms lunch for tomorrow then my moms bf comes down stairs cussing at us and I’m not her so I’m not going to let some man talk like that to me so I defended myself and of course that pissed him off so he told me to go back to my house. Which pissed me off because HE DOES NOT PAY RENT. Mom then comes down and tells me the same thing like really?? I was making you lunch, I’m your daughter, I was there before him, I was there when we didn’t struggled and had nothing and you’re on his side?? LIKE WAKE THE FUCK UP MOM. I want to talk to her tomorrow (today) when I go back home and tell her I’m going to get my shit together because I don’t want to be like her. I will never kiss a mans a*s, I will be cutting ties with my mother because I don’t want that kind of toxic energy around me, and it’s sad because I know I won’t be able to see my siblings anymore but I have to do what’s best for me.