My parents make me want to kill myself?

Whenever I'm around them I feel anxious and depressed. Everything, and I mean LITERALLY everything that they say to me is something negative. It makes me go into my room and hide under my covers in complete darkness for hours. I'm a good kid, I clean and babysit, don't drink, smoke do drugs or anything. My mother yells constantly everyday to the point where I dont even want to wake up in the morning. My father is the ultimate demise of me. He makes me feel worthless with every insult and name he calls me, he just uses me. I can't even hold my head up to look at people anymore because I feel ashamed of myself. They call me ugly and fat. Every night I just cry in my room alone thinking of ways that I can end my life, I'm pretty much tired of existing. I have no friends or family or school teachers to talk to!!! I'm a shut in that's never aloud to leave the house. I used to be physically abused. What should I do?