Dear Annie: I’ve been married for 26 years. I have a 24-year-old son at home on the autism spectrum, and his 4-year-old daughter, of whom he has full custody. They get by with my help, and money, of course. I have always been a very loving and supportive husband. I cook, clean, do laundry and whatever else needs to be done. I’m getting older now and developing arthritis. For a while, I would…