Sex at 65

I am a 65 year old woman, my husband of 40 years is 77. Here's the question, I have no desire to have sex with my husband. He has a hard time preforming.. I have COPD and ibs. He says there is something wrong with me. The way he talks to me and calls me names has just turned me off. He has a problem with my oldest daughter. He raised her since she was 3years old, she is 44 now. I need some one to advise me on what to do. Let me know if I'm OK and how to explain to my husband what is going on. Oh, communication is non existent. He tells me he doesn't want to talk to me because I always want to start a fight. I do not like fighting. I can't ask any questions because that means I want to start a fight when I'm just trying to get information so I can follow his story.
Before retiring my husband would be gone for weeks at a time working.