Dementia, in any form is very tough. I know it is REALLY hard to deal with. We just received a diagnosis of Lewy Body dementia for my husband's grandmother. We've been helping take care of her for years. I've gone thru the anger, the emotional detachment, the sadness, and now humor.
I think you can find some tremendous support in online forums if you can't find anyone locally. You do need to talk about it.
Also, if you ever feel as though you are in danger, don't hesitate to get immediate help. It's not your mom, it's the disease that is causing the anger and aggression.