My 82-year-old husband has FTD. His obsession/compulsion is sex. He is unrelenting in his desire. He can’t function due to prostate cancer. Suggestions?

This is so stressful. I feel like I have to avoid him to be free from the ongoing pressure to please him. He can’t get an erection. He touches me all the time and it upsets me. I think he goes back to the days of our incredible sex life when we were in our 40s and 50s. I explain that it can’t be anymore, but when I refuse he gets mad, or moody or I get the silent treatment. I love him dearly but have no interest in this form of intimacy. I’m happy holding hands. He takes an antidepressant and Ativan but nothing helps with this. Does anyone have the same problem? Any suggestions? At least he isn’t watching pornography, thank Heaven.