I must be a horrible person?

Basically the only way that i will end up hanging out with people is if i pay for the fun...fine **** it im being used. They constantly put me down for no real reason but i wont lie, sometimes there is a reason and i cant really argue against simple logic. I would take a bullet for these people and they wouldn't give a **** if i died. If im not around any of them, im by myself. After being used, obviously lied to, put down and made fun of, it really doesn't bother me, i guess im such a bad person that that's the only way that i'll ever have any human interaction outside of "life". I realize that if i want to hang out, drink a cold beer, im gunna be the one buying the beer. The only thing that gets to me is when one of them talks about **** they don't know about. Its only happened twice. My question is what should i do the next time that it happens? I don't want to fight but i can almost guarantee it will end bad if i say anything...im on my way back to being a complete loner again. I try to let everything go, i hear the obvious lies and go along with it, spend all my extra money, i try to be dependable, everyone uses me, I know it and i don't do anything to stop it and for what? Im gaining very little and giving too much.