Hi Butterfly,
Your mom sounds alot like mine. I know the rage, pain, frustration, and feelings of shame that come with having a mom who can't see or hear me. Can you take a break for a few days and take some time to take care of yourself? When my mom starts the blame game, I leave immediately, and when I get home I tell myself over and over again that her words are her illness (NPD) talking, and if she were healthy she wouldn't treat me like that. It helps me detach from the situation. Then when I am away from her, I decide how much contact I will have with her. What I will do while around her, and how long I will stay. This helps me to keep from feeling used by her. When she starts her stuff, refusing to react helps me too. I say "oh really", or "how interesting", then I process my own feelings when I am away from her. I do this because I know that apologies from her will not be coming, and any attempt I make to get her to hear or see me will be futile. And I remind myself over and over that it is okay to feel the way I feel about my mother, and even though she can't hear or see me, it's still okay for me to feel what I feel.
You have so much to deal with right now in dealing with her N characteristics and her cancer. Take good care of yourself. ((((((Butterfly))))))
Lynne