I dont know what to do anymore?

ive been depressed for years which is sad because im only 15 i have so much on my shoulders it feels like i could just colapse sometimes. i live with my mom and my grandma and brothers. my grandma supports us because my mom cant and they are constantly fighting over everything mostly money but most of all they complain to me. i sware if im alone with them for 1 second they start bitching about the other and its always the same things i tell them to please stop that drives me crazy but of corse the never do and now its even worse because my grandma lost her job. along with this its my first year of high school and im already sooooo stressed i cant focus and school and forget alot so i havent been turning alot of things in and my grades are lowering but i have to do good and get into collage and make a life i know that i would be the 1st in my family to do so but i just dont know if i can im also not social at all. i dont want to join clubs .my mom wants me on meds for this but i dont want to..what to do?