Sounds like you have a lot of negative influences in your life. You should cut them out asap if that is how they are going to treat you. You made a decision. It didn't work out. You should be commended for having the bravery to try it.

Seriously though, you are only 20. You have your whole life ahead of you. People are right here to say you need to stop sitting around and feeling sorry for yourself. Put that energy into getting a new job. Any job. Just get yourself out of the house. Work your ass off to build up your resume, hack projects on the side, contribute to open source, etc.

Don't commit suicide because that is just stupid and nobody is going to feel sorry for you.