I dont know what is wrong with me!?!?

well i have a pretty screwed up life , i live in a house with my dad a stepmother who is constantly calling me names and always thinks im doing something wrong when its really right a stepbrother who never talks to me another stepbrother who practically loves me (i guess) and then a baby sister and a little brother , the point is i am just sick of life like honestly why was i put on this earth ,to be made fun of because of things that dont even matter , to be depressed all the time and i always hide my depression , and coming home to here my stepmothers mouth about how ugly or bad i look or how bad my outfits look or how my friends are bad examples for me and i honestly have mental problems about my self image and she is driving me over the line and so is everyone else and im just sick of it . what should i do ? and if you read this thank you so much.