you certainly seem like you are in a rather tense situation; are you sure that this taking care of your brother is not over your head and perhaps should be done or monitored by someone with more expertise than yourself? This situation, just reading about it, certainly intimidates me, for one.
I know I would be asking God for instructions to make the situation better for him and for yourself. That is what I do when I am over my head, and even when I am not. God is certainly knowledgeable about how and what to do and when to do it, so He can make your situation better in short order. Thats just what I would do.