Im 13, I hate my LIFE. I wanna die!?

Im overweight , im ugly, and my life is so useless. Ever since i started sixth grade, my grades have been going downhill. I made honor roll every grade. Now i have D's and E's. I also hate how I look, everyone says im so pretty, or beautiful , but i know im not. I have a gap in my teeth, but im getting braces in a couple weeks so i dont really care about that anymore . Im also overweight , like 180 some pounds . I cut myself because it hurts my feelings when people pick on me about my weight , and say mean things about me. People call me stupid cause I cut myself, but I dont care. I wanna starve myself so i can get over this 'fat phase'. Some days i love life, others I just wanna lay down and die. So how do i starve myself to make me feel prettier inside and out? And what should i do about the way i feel about myself?