Long story-but I need serious family advice only please :) thank you.?

HI All! So I need an outsiders opinion b/c I have no one to talk to. Here's the thing: I'm 24 yrs old, college student, live at home in the garage where there's an apartment and I pay rent. A few weeks before Christmas the roads were a little snowy and my parents were driving drunk to pick up my 17 yr old sister from work and they ran off the road and smashed into a tree. My mom recently had to get surgery with metal plates in her b/c the airbag broke her collarbone, and thankfully my sister and dad werent hurt. Before the police came, my parents called me and told me to rush down to the scene which was only 10 minutes away and tell the tow truck guy and the state trooper that it was me driving. I didn't want to do this but I did. I have lately been very resentful and have little respect for both of my parents for driving drunk w/ my sis in the car, I feel like crying just thinking about it. Anyways, I've been a little on edge towards my mom and I haven't been the nicest. I'm finally sticking up to her verbal put downs she's been doing to me for the entire life, and she's not used to it. For the past week, I havent even been able to come in the house (Im in the garage remember) and I'm not allowed to eat any of the food or drinks nor can I use the washer and dryer....she's telling me I have to go to the laundromat now. Today is my bro and sisters b-day-theyre twins and 17 yrs old, and I wasnt even invited to go to the usual b-day dinner and cake. My sister is on my moms side and if i say the slightest thing to her she doesnt like, she imm tells my mom and then my mom screams at me...i feel like my sis is wanting to start more trouble ? I deep down don't really care that much b/c as long as I can remember, her and my stepdad (who's been there since I was like 2) have talked down to me telling me I was dumb, lazy, not going to go anywhere in life, etc. I'm finally sticking up for myself to her and she wont let me int he house like a psyhcopath. What do you honestly think of the situation and what would you people honestly do? I hate to say it, but I truly in my heart believe I can live without all of them. I don't get any happiness from anyone of them. Thanks very much! I needed to get this offa my chest and tell someone :)