Tammie,
I actually got past a lot of that emotional responsibility for my son over this past year. That detachment was one of the hardest things I've gone through. It feels so much better now though. Sounds like you may need to do the same thing with your father and brother. The hardest part for me was feeling like I was keeping my son alive and if I quit he would die. I can imagine you must feel the same way. I actually had to risk him dying to let go. That was so so hard. He's still alive though and I'm so much better. I can still talk to him and don't have to feel responsible for him. I started by telling him that I would not discuss any problems that he was unwilling to do anything about.
Many hugs,
MG