What shuld i do about my dam mom.?!?

Okay so rite now I'm thoroughly pissed off @ my mother me & her hav never had a gud bond nd now its gotten even worse b/c im a sophomore in high skool nd she insists on jus throwing me off into the world to fend for myself.! Anyways so yes I'm a band geek so we had to perform @ a game & after me my bf (oh yea I talked to him nd now were gr8 thnx.!!) Nd sum frenz were gona go to our skool play after wards buht unfortunately I'm @ home bored watchin my lil brotha b/c my mom made up some lame excuse claimin I yelled @ her ovr the fone.! 1) I'm sick I can barely talk 2) I was in a room full of ppl who woundt shut up so I culd barely hear myself nd when I tried to explain to her she hung up on me lyk a child so now to top it all off my mom has left us @ home by ourselves again.!! She does this all the time I've never known a time tht my mom hasn't came home for nights on end nd me & my baby brotha being here alone all the time now I hav no kids I dnt plan on having any till I'm gud nd older buht she specifically yelled @ me the other day sayin tht he is my responsibility.!! I mean wats wit tht.?! Now I understand tht she jus got out of an abusive marriage wit a big *sshole of a man who won't even come see his own son & she's ben stressed b/c she also found out tht her own father tried to rape me(long story for another time) buht she's my mom not the teenager of the house.! She's out more than I am.!! She's constantly gone & comes in @ very unappropriate times of the night or sumtime not @ all (lyk last nite) buht she yells @ my sister wen she comes in late or stays @ her boyfriends house.!! idk wat to do about her then when me & my older sis try to talk to her she never listens b/c she has to be sure to stress her stpid points all the time.! We dnt kno wat to do.! I'm currently contemplating on whether I shuld leve buht I kno running away from the problem won't ever solve it buht I just wana get away.!! Wat do I do.!? Sum plzz help.!!