I don't recall how old you are ((Teen Idle)) and whether you could move out independently or not. I'm going to share a bit about my own history and hope it helps you. First of all - often when people are very depressed and dysfunctional, its like they're in a tunnel. They only think of themselves and can't see other people's feelings.

I was 2 when my father died and my mother was left with 5 kids...me being the youngest. My older 3 siblings got married and me/my brother were left. By the time I/my brother were in our 20's, my mother was getting older with some health problems. Both of us were overly attached to my mother and I felt guilty about moving on with my life. When she suffered a massive stroke, I prayed to take her place, but she survived disabled. My brother never moved on with his life until she had to go in a nursing home. I got married eventually.

What I'm trying to say is - sometimes dysfunctional families hold other members of the family back. You're wonderful for feeling responsible, but you need to think about your own life too. Your mothers an adult and she shouldn't load your brothers death on you - you're grieving too. I hear a lot of passive/aggressiveness in your mom's statements. Eventually I had to loosen the apron strings a little. My mother became too dependent on us emotionally. Maybe her moving with her mother would be a good idea or is this just a ploy? You're young and need to think of your future.