My boyfriend is disabled, and I want to dump him, but everyone will hate me? HELP!?

My boyfriend is disabled, but he's a little strange. He has a mild form of muscular dystrophy (?) and lately it seems like he has been trying to get attention from it. A few days ago he dumped me so he could go out with another girl (whom he has only ever talked to via Facebook) but we are now back together. Also about a week ago he told one of my friends that I asked him out and he said no, and everyone got the impression that I was telling everyone that we were going out when we weren't (but we were at the time). He told me that he only lied to her because I told 2 of my friends about the relationship. I really like him, but I can't escape the feeling that maybe things are better off if we stayed friends. I've already been judged as by a liar, as I made the move to ask him out in the first place, I'm worried that he might tell people that I led him on. My social life is in shambles anyway, but I'm at my wits end. PLEASE HELP. :/