I'm about to flip out..?

kso, my older sister who has been in college for 2 years now, quit her summer job because she didn't feel comfortable there. which is reasonable in my mind. but my mom flipped out saying that she should have just stuck it out for the summer because you're never going to like a job. then she called kaitlyn (older sister) a spoiled *****. then came into the licing room with me and my younger sister, and called us both spoiled bitches and started freaking out at us. she was taking her anger out on us. now, 2 weeks later, she still won't speak to any of us. all she'll say is 'yeah' 'okay' or 'whatever' ... i even said i love you and she said 'yeah right'. i have to drive fore 30 minutes with her every morning to my day program rehab. and her doing this is making me stressed, and stress leads to me using drugs. she doesnt realize this. but i'm actually going to freak out at her any minute now. she's taking her anger out on the rest of the family for something she shouldnt even be mad at ANYONE for. she even said the whole family hated her and junk.. and she's actually had to take depression pills because she thought the whole family hated her beofre.. what do i dooooooooooo?!?! D: i feel the need to use drugs really badly..