my mom is a brat to me

so im 15, and i know this is when everyone is saying "oh i hate my parents", but i actually hate my mother and i really need to talk about this. my little sister is a cheerleader and my mother is more concerned about her and the girls on her squad, she goes to all her competitions and practice, but me, im a black belt in martial arts, and i am a 2 time defending world champion, but does she care? nope. in fact, one girl on my sisters team got pregnant a few years ago, and when my mom gets mad at me she immediately says "your gonna end up just like her, and when u do end up pregant at 16 you can find your way out of my house", she could be getting mad at me over not vaccuming the carpet, and thats what she says. and i dont ask my mom for a lot of stuff, i asked her this morning if she coukd pick me up a thing of pads because i had started my period this morning. she got home and threw  the pack of pads on my bed and i said thank you, and she said "WHY DO YOU ONLY COME TO ME WHEN YOU NEED SOMETHING WHY DONT YOU EVER ASK YOUR DAD TO GET YOU PADS FROM THE STORE" and i said "because dad doesnt know what to get, heck dad barely knows what a pad is, and hes a doctor" and my mom replied with "HOW DO YOU THINK HALEY FEELS NOT HAVING A MOM?" but im like "okay whos haley" and she goes "The girl on your sisters cheer team". im so tired of being compared to stupid cheerleaders. okay so what if Sarah over there ended up pregant, or is susy got an F on her report card, im not them, im straight A's, black belt, skeet shooting. but also if one of those cheer girls does something or wears certain makeup or something my mom will tell me that i domt try hard enough, and that unless i look like one of the cheerleaders on the team then i will never be good enough or look decent, and im tired of it. when my mom talks anout me to the other cheer moms or her co workers, she talks about me like im an embarrassment and it makes me feel so bad about myself and i cant stand it. my mom is such a brat and tells me im not pretty and she puts my self esteem in the garbage. 
(this is me btw) 
any advice? last time i tried standing up for myself against her, i screamed at me until i started crying and last summer put me through a stage of depression