My mother is a recluse and lives with my husband and I. She did not want to go to the doctor when she became very sick. I could tell she had bronchitis so I kept asking her to see a doctor. She would not go. She finally listened to my husband when he told her that he thought she had bronchitis and feared it would turn into pneumonia. My mother told me she would go because she was tired of hearing me ask her over and over to go to the doctor. She did see a doctor and she had bronchitis. The doctor had difficulty getting my mother to take deep breaths when examining her. She was indeed very sick as I suspected, but she would not listen to me and that made me mad. I am glad she went to the doctor. How do I deal with the anger when she does not listen to me when I just want to help her?
Back, to mom and away from reminiscing, the anger and comments, unfortunately are part of the disease. They are not really directed at you, it is largely their frustration in that they can no longer care for themselves. So, you just need to ignore the comments, turn your back, and my favorite part, roll your eyes, thinking here we go again.
One thing that helps is if you quit asking her to agree and start telling her how it is going to be. "Mom, if your cough isn't better tomorrow, we're going to the doctor." In the morning, say, "I called the doctor and told him your symptoms. He said to bring you in." (Lie if that works. There is no sin in it. You are lying to help her get well.)
Another help is to recognize that she is no longer a rational person who makes sense. You don't expect a 3 year old to agree to go to the doctor, and you don't take the kid's tantrums personally. You might feel angry at the trouble it causes, but you don't think that a kid that young is doing it just to annoy you.
Maybe your mother is partly trying to annoy you. Maybe she always did torture you one way and another. You will be happier if you keep telling yourself it's only the disease. You will be able to be kinder to her if you keep telling yourself it's only the disease. You will get to heaven sooner, and she will even behave a little better if you can (one step at a lime, one inch at a time,) stop taking it personally and decide to feel pity and compassion for her.
No blame here. We all try hard, and we all come up short sometimes. When you can replace anger with compassion or pity, you will find it a little bit easier to bear.