Hiya Flossy,
It sounds like it's time to cut bait and take a loss here. That's what i would do if I were you. You can only help a person so much, they have to want to get better too and it doesn't sound like your bf wants to from what you posted or his family for that matter. Sometimes families don't want the sick person to get better because then they would have no scapegoat. Plus it would change the family dynamics and that means that everybody would have to change.
You have to take care of you first. There are certain things that only you can do for yourself and number one has to be your mental health and well being. Nobody deserves to be treated as you are being treated. Being told it's not all about you is repulsive to me because sometimes it is all about you. And what else, does he think it's all about him if it's not all about you?
I know sometimes I keep the relationship I have for fear of never finding another one. This just keeps me stuck though and not moving forward like I'm meant to. I hope my advice doesn't sound too pushy, i'm not trying to be, but sometimes my protective mother hen comes out

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Love and hugs,
Tara