What shall I do if my mom Abuses me?

I'm 16 years old and my mum only started abusing me after my baby brother was born and hes 5 now. Like sometimes i don't say anything to her but when she says something stupid i don't say anything i just look at her and she says something like "Don't look at me like that, i'll rip your hair out". I always clean the house when she asks me but when she comes back from somewhere she just gets more rude and shouts at me even if i cleaned. I've also noticed that she loves being horrible to mw after seeying her friwnds or infront of them. Sometimes if i make one little mistake she calls me either "*****, stupid, ugly". Also if i just laught about something shell go "why you laughtibg? You thing your a princess? Your spotty and ugly". She always says that im stupid and everyone esle is smart, she always pulls my hair and bruses my arms when she digs her nails into my skin and punches my arm. If i say something shell start arguing even if im right and then shell call me stupid again. Also she kicks me sometimes and erghhh :( sometimes i do love her when shes nice and i never hit er back or anything. But she just makes me want to die..Even now she pulled my hair and called me a ***** and told me to go to my room for telling her to calm down because everything is allright with the ps3 game that my baby brother was playing. She always says that she loves my baby brother in front of me which just brings tears in my eyes because ive never jeard her say that to me..Why cant everything just be good? :(( I feel horrible..she also likes to say that she cant wait till i move. Or shell call me fat even thought i hve a contract with a modeling agency.. She always tries to make me feel really bad and hurts me physically as well as mentally..i dont know what to do anymore...Please help..