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Cary's advice is good. Changing just a few details, your story parallels my family's life. (Changing a few more details, it probably mirrors the lives of hundreds of thousands or millions of families). I would add that, whenever possible, family members should consider confronting the stigma that attaches to mental illness. When my brother first got sick, I remember clearly how all the people with broken legs, with diabetes, multiple sclerosis, got huge community support and comfort (and casseroles delivered to their door). Whereas for mental illness, my family was left with complete silence and isolation. One way of dealing with the tremendous loss you are encountering is to work to reduce this stigma so that others in your community will know more clearly how to help friends, family, and neighbors when mental illness strikes (and sometimes before it gets out of hand). Your local chapter of NAMI is a great way to start.
And, emotional abuse is emotional abuse regardless of the cause. Some of my family members with mental illness are extremely abusive, while my brother is not. He's taken the steps necessary to take care of himself emotionally and avoid abuse, even when he can't always control his mental illness. You shouldn't have to willingly subject yourself to abuse.