I think you are right about a lot of things. Older people don't change. People, in general, don't change. (Not just because we want them to.)

It's great that you have accomplished so much and now enjoy working in your profession. It's great that you appreciate you husband being hard working. Sounds that there is a lot in your life that is successful.

Big change is too much for you. Try being a tiny, little bit less attentive to parents-in-law. Jump a little, tiny bit slower when they want something. Become a teeny, tiny bit more hard-of-hearing when they call for you. Once in a while, accidentally forget some little thing that they told you to be sure and remember. You will find that it will not be the end of the world. Those can be your quiet, little victories. You can change a little, tiny bit at a time.