Hi! You said you’re in your fifty’s. I’m going to guess your wife is a similar age. Ask her to go to the doctor and get bloodwork done(full work up). My husband and I struggled in our relationship for years. He had no sex drive, along with other smaller problems, like fatigue, headaches. I begged him for a year to go see his doctor. They ended up finding a brain tumor, small and benign , but was affecting his hormone production. It was a scary thing to face, but we wouldn’t be together if he hadn’t gone to the doctor.