Been there, done that, Try to come from love and leave your ego behind, They need to feel loved even if they don't remember who you are. Sometimes we don't know who they are.
If possible get a break. Hospice if you have it can arrange a break. If not do you have a friend, relative or neighbor who will help.
My husband was driving me crazy, but my neighbor thought he was funny, she loved him, and I got a very much needed break. Some day this will all be just a memory.