Sadsic, don't give up! Of all the shit you've been through, why would you do something terrible to yourself now? You've been through the worst of the worst, and now you should benefit from making it through those awful times. It can't get any worse than some of the things you described, and you have to live with all those memories, but just think, whatever you go through from here on out, it can't touch that. It's like ending a trilogy on the second movie! As cheesy as it sounds, what if Star Wars ended after The Empire Strikes back? What if Luke gave up and said, "well, my arms gone and shits fucked, so I quit"? That'd be terrible! For all the bad, good will happen Sadsic! Please just don't give up hope though!
I suggest that you start working out. It clears your mind, you'll start to look better, and you will feel better and better about yourself every day. Trust me, please just give it a shot. You'll feel like a completely new person after the first week, then the first month, and even more after a year. Fuck those other people. Go to a gym, and unless you live in like some hard-ass area, nobody is going to make ribs at you.