What did I do to make my parents treat me so horribly?

I have severe depression that I have learned stems from emotional abuse from my parents. My entire life they have made me feel bad about myself, they are constantly belittling me and making me feel like everything is my fault. My mother accuses me of being one of the sole reasons for her own depression. My sister constantly treats me like I am below her and like she is smarter than I am and treats me like I am an idiot. My father is a horrible man who doesn't talk, he yells. The only one I have is my brother. He treated me like any brother treats his sister, but when he moved out we grew apart and I know it is because he went through a lot of the same stuff.

I am 25, still living with my parents and older sister because I can't afford to live alone, as recently as yesterday I have been belittled and used as an emotional punching bag when my mom told my brother that I upset her all the time right in front of me. I see no end and bringing it up will only make it worse on me. I have tried saying something to them, then they treat me worse. I feel like they are all narcissistic and they project their problems on me because not only do I suffer with depression, but I also have anxiety, autism and bipolar disorder. I am not in any way perfect and have never treated them horribly, but they take advantage of the fact that I am vulnerable. Does anyone go through this? How have you gotten through it all?