My brother is a drug addict and he doesn't really speak to me either. Over the years I have helped him a lot with employment opportunities, loans, support, etc. When I started detaching and having better boundaries, the relationship kind of dissolved. It hurts my feelings, but I also understand that he will not have anyone in his life who does not enable him.
I think both addicts and alcoholics choose the people in their lives according to how they can serve them or meet their selfish needs. I would not take the situation with your brother personally. I know it hurts though.