It sure sounds like you have a plate full! Raising our children is so very hard in itself and then to have the concern added for a struggling loved one..... I understand your desperation.

I have a brother who I worry about so much(and I'm rasing two teenagers)..... he's in self-destruction mode and will not get help.
It seems to me that it's a good thing your brother is getting some counseling....... have you ever thought about going to a session with him?... would he be OK with that idea?.... that is, if it's something you would consider. Then you might know better what is going on with him and also the counselor will be aware that your brother has someone out in his life that is there for him.

I hope he can get things under control real soon.... before too much damage is done to his health and his employment.

Oh yea, and Welcome to PsychCentral!