My mom is 72 and has lived with me for 2 years. She has limited mobility, but is able to take care of her own basic needs. As a child and young adult, she was verbally, emotionally, and sexually abused. Until her abuser died 18 years ago, you would never have known that she had been abused in any way. She was a good mother and role model. We were very close. Since her abuser died, she has become critical of EVERYTHING, and very demanding.
She has gone through therapy a couple of times and is on anti-depressant medication. She does not want to resume therapy, although she needs to. I have gone through therapy for my own sanity in being able to deal with her. For a long time, she would have several days in a row when she would be in a good mood - approachable, laughing, joking. Then she would have a day or two where she was just the exact opposite. Now, that has reversed. Even though physically she is not quite to the point of needing nursing home care, I feel like if something doesn't give soon, I'll be the one heading for a nursing home!!
I guess I'm not looking for a quick fix (but that would be nice!). Just blowing off a little steam.....
But, ironically it was when I saw it leaching over into my own small family, that I revolted. I will protect my family from it happening to them, but before the rot progressed, I tried to protect them from knowing. What good would ill will have? Now they make up their own minds.
Talk to your mom. Ask her if she needs to get good and mad, and tell her you will get good and mad WITH her if she would like, but you refuse to get good and mad AT her. We abused people feel we deserve bad things. Maybe she wants you to dislike her because she feels she is not worth loving. It is a terrible conditioning, but it is a deep rooted one. Then ask if there is some way she would like to vent all of that misery in some positive way. Make her UNDERSTAND that you are there for her, that you love her, that you appreciate everything that she did for you. That she is a good mother and you love her, Period.
I know how hard this was on my husband, and I know it must be extreamly hard on you as well. We are all here to vent and find help. I hope that you do. It has been a huge help to me.