Was it right to leave my bf because of his disorder?

I was with a guy for 6 months and he fell deeply in love with me. I came to realize I wasn't in love with him though, despite feeling close to him in some ways and after we split he keeps trying to get back with me. After we broke up he also revealed he has multiple personality disorder and it explained alot of his contradictory and erratic behavior. He was really afraid of telling me about it, but I already knew there was something up. It made it really difficult to tolerate him alot of the time, but I feel very bad. He is a really sweet guy and probably the best guy I've been with in many ways, he treats me respectfully unlike many guys I dated in the past. Am I making a mistake for not staying? It's so tough because I am also not very physically attracted to him. I told him he needed to lose weight earlier in our relationship when he asked me my opinion on his looks but he got really hurt. What should I do? If feel if I leave for good I will never find a guy that treats me well because I keep attracting s.