I know that the Ten Commandments require us to respect our parents. But not all parents are worthy of respect. I am disgusted by the things my mother has done. She is old now and needs me, but there is nothing in her life that deserves respect. How can I respect my mother without losing my dignity?
Respecting your mother doesn't mean that you think she is all good. But surely she can't be all bad. Surely you can think of some redeeming feature, something good your mother has done. There must be something for which you can say that she is a worthwhile person. Can't you think of one good thing she has achieved?
I can. You. Respect for parents is a base for self-respect
Like it or not, you are a product of your parents. No matter how different you are from them, no matter how far you go to avoid repeating their mistakes, you will never be able to change the simple fact that they are your parents. Whether they were good parents or horrible parents, whether they built you up or put you down, they are where you come from.
Your mother brought you into the world. If you honestly think your mother is all bad, without a good bone in her body, then on some level you will see yourself as another one of her failures. Your existence stems from her. Respect for parents is a base for self-respect.
The fact that she mothered a child who has a clear sense of right and wrong, and is aware of her wrongdoing, means she must not be all bad. She may not get the credit for your moral sensitivity, but she does get some credit for your existence. If nothing else, you can at least respect her for that. Far from compromising your dignity, respecting your mother forms the basis for your dignity, because she, along with your father and G-d, was a partner in your birth.
Respect does not mean accepting her failings or excusing her misdeeds. It means that if your mother needs help, you should be there for her. When she speaks, you need not agree, but you must listen respectfully. You have to treat her as a mother. Failing that, your self-respect has shaky foundations.
You don't have to respect the life your mother has led. But, for your own sake, you do have to respect that she is your mother.