I’m so very sorry for your loss of your brother. And I’m very, very sorry that your family is falling apart in the wake of his death. It sounds like the whole family is having tremendous difficulty coping. You are grieving. Members of your family are grieving. Your brother’s death may have brought back unresolved feelings about your father’s abandonment and death and your mother’s rejection as well. No wonder you are feeling overwhelmed.
People grieve differently. Some become sad. Some are mostly angry. Some shut down. Some push it all away by being hyper-functional. Some do a little of everything. I imagine you are seeing different reactions in different members of the family. In you, grief is pulling everything that makes you unhappy to the top. It’s normal but I know it’s very uncomfortable to feel so not like yourself.
Fortunately, you live in an area that has a mental health center that has a sliding fee scale. Check this website for information http://www.healthehurt.com/programsbydirections.html
I think you need to talk with a professional to help you sort things out and set some reasonable priorities for yourself. If you go and have a positive result, it wouldn’t surprise me if other people in the family eventually also seek out some help. As hard as it all is, it may also open an opportunity for some healing.
I wish you well.