Help me, I don't feel happy anymore?

My dad is always yelling at me and whenever I ask my mom a question he gets irritated and yells again. He's always bringing up things that I didn;t do perfectly, even though I do my best to do things perfectly. My twin sister is always treating me like crap and calling me a skinny b*tch and no one at home is really nice to me anymore. I used to be really really happy all the time and everytime something like this happens I feel the happiness in me diminish day by day. School's over for me so i have to be at home everyday now, because I have nowhere, so I have no 7 hour escape. The only people/animals that treat me nicley is my brother, my dog and a kitten. I was wonder what i should do about all this. And please don't say drink I'm under age