I think what you are describing is a natural defense mechanism. Sexuality is one of the strongest human emotions and touch is one of the strongest human needs. To be in a relationship with someone who has provided both and later denies both is deeply troubling, deeply painful, and raises all kinds of self doubt.
At the 40+ years of marriage mark I found myself in a sexless marriage. The change had been gradual, sort of like the story of boiling a frog. Didn't notice the changes over the years. In fact, we did a visious cycle dance. My wife withdrew from me emotionally, wouldn't offer any praise or social reinforcement, I looked to work for success and praise, which caused her to feel even more abandoned. I thought I was being the good provider, she felt alone. We both drove our marriage into the ground. It got to the point that I said to myself it had to change or I was going to divorc her. I decided to try my hardest to save my marriage and ultimately my wife decided she preferred marriage to divorce, but it was close.
From my personal experience, I really wondered if my wife found my body repulsive. During therapy she said that wasn't the case, it was her and not me. I now believe what she said. I also got so angry at times. I can understand why spouses in such situations cheat as a way of revenge, self-image protection, and to possibly sabatog the marriage. Luckily for me I read MWD's SSM book and in small print in the back found a reference to this website and logged onto it. That allowed me to focus my mind on saving my marriage. The people here helped me with their experiences and pointed me in the direction of some great authors.
Good luck to you T-Mom
>43 years of marriage--My wife and I are now closer than we have been in decades. I believe that my SSM is over.