So confused!!!! Help please!!

Me and my mother don't get along. Since I was small she would drink and smoke and ignore me. Would hit me for the very littles thing I ever did. Growing up as a teen I was going trough depression, it got to the point I hurt myself I would do drugs and take pills. I didn't want to attend school and I let my mom know about all that all she said was I was going trough a stage. My brother came to live with us and he would work after work he would come home drunk he would try to beat me call me names and my mom would allow it. In fact he hit me twice (I called the police but my mom would defend him) and he tried staping me once when I was pregnant. I have two daughters in which I hadnt been there for a while due to me working and going to school. (Their dad never helped me and we ended separating)
So now I have a new partner, he pushes me to go to school to better myself. He buy my girls the things they need he pays rent(we still live with my mom and brother) and he pays all the rent because once my mom isn't working my brother is but doesn't help .
So yesterday me and my partner had a couple of beers, it ended in a argument but we fixed it up. Well today she comes telling me that I'm a big alcoholic and if that's the example I want to give my daughters . And that why was I crying and if he's hitting or abusing me(none of that's happening) and she just started trying to put things in my head so I can leave him. She then said that I should pay her because she with my daughter 24/7 and it isn't fair. Well that's a lie she doesn't have to pay rent she doesn't have to pay for food and the only time she does see my girls are sometimes at night when I have to go to school. 
Well my boyfriend told me that we should move out he already has a place and all but my concern is my mom!! How will she do it to pay for rent or food.... Should I leave and do my life or stay with my mom ?? 
Sorry it's so long ...