Is the way my mom acts toward me ok? Who is in the right?

I'm 18 and live with my mom and her husband, and will be moving out soon . My mom is an alcoholic and so is her husband... I was in the states custody and living with other relatives until I turned 18 .. I came back to my mom because she begged me even.though I was taken away from her when I was 12. When I first came here she pulled my hair and made my scalp bleed when she for drunk one night for no reason literally , and she here mad so easy and says things that tick me off like saying , go move in with your boyfriend , oh wait he probably won't have you over there , cuz he prolly just wants you for sex . Or shell say nobody wants you living with them, that's why you had to come with me , and that's why you've been in so many foster homes ( even though that's just the way they do it , and she begged me to.come with her . I feel like mature mothers don't say things like this to their kid ?? Like once when I came to visit her for Christmas when I.was 17 she got drunk and started fighting with her husband and I wanted to leave and she put a knife to her throat and also hid my phone so I couldn't leave and wouldn't let me out the door .. is she crazy ?? Should I cut all ties with her ?? All she does is bring me down ...