Living with an extremely bipolar mother who refuses to get help

When I was 1 my grandmother took me away from my mother because she was unfit and raised me for 16 years. From the time I was 4-16 I didn't see my mother and had no contact because she moved away. During that time my 2 younger brothers that were living with her were taken away because of her coke and alcholol addictions. I'm now 19 and have been living with my mom, her boyfriend who is highly addicted to oxy 80's and his son for 2 years. The first couple weeks of moving in I noticed there was something wrong with her. She is emotionally abusive and does not stop freaking out even if you ask her nicely. I cook, clean and take care of her 2 dogs and my step brother because she is always out with her friends and yet nothing is EVER good enough. Example I wake up sweep mop and do dishes and when she gets home it's like WW2. it's gotten so bad I'm away from home as much as possible. She contioniously make threats and it's hard to tell her anything or have a conversation with her because it turns into her freaking out. From the minute she walks in the door it's her yelling over little things. She is very selfish and ignorant, everythin is hers no one can touch but her friends (example; something as simple as a can of pop) and she's got to have everything she wants right away or it's WW3. She is a compulsive liar, lies about the simpliest things example: I broke my ankle and she told everyone that the doctors were so stupid they xrayd the wrong foot. She CONSTANTLY tells her friends lies then she asks me to back her up on them. If I forget one of her lies and tell the truth I get screamed at by her. She has an unhealthy obession with control, she has to know everything that's going on. It's like she gets high off of it. She buys pills for her boyfriend (60$ a day) and he just got out on bail for breaking into 3 pharamacies. She also refuses to get a job, last job she had was a stripper 5 years ago and resorts to drug dealing to support the family and her boyfriends drug addiction and she constanly complains about not having money when she makes 300$ a day. I'm saving to move out as quick as I can but i want my mother to get better, I'll love her no matter what. I've told her before to get help she agrees but never goes. I really need help on what to do, I'm at my witts. I've researched bipolar symptoms and I'm not a doctor but she fits everything perfect. Please help