Why should I keep living?

Hello. This must be a very disturbing question to read, but it is true. I do feel sad, and depressed right now. I am 14 years old. I live in a family that's poor, and I ALWAYS no matter what, get into trouble. Right now, my so-called 'friends' ditched me and never try to contact me, and ignore me. & @ skool, im the outcast that don't belong to the preppy ***** group, neither do i belong to the nerd/'interesting' peope. And have more problems to deal with. I feel....I feel like not living anymore. :( please, i need a helping hand. my niece always puts me down like "nicole, u need to get active because your fat. " or "you're ugly, and stupid." and my brother always complains about me, and he cries alot because of me. My mom ignores me, and gets mad at me...my sister makes me SO angry. i feel like punching her.! and my dad is a cronic drunk. i do not feel like living anymore in this sucky world we call 'home'. its hell. if you can help me, please suggest what i can do!! how can i prevent this in te future??? ... sorry if i dont make sense.....i dont feel like i do either...