This One Is A Little Embarrassing. I Am A 79

This one is a little embarrassing. I am a 79 year old Ph.D. male who is basically sexually inactive due to the lack of interest from my wife of 56 years. About three years ago, I became aware that my penis was extremely sensitive to the point that I touch it through my clothing compulsively or habitually. I am a lay leader in my church, a gentleman, and a strong family man. However, this has begun to be a marital and self-esteem problem that has to be stopped. Is there a way to desensitize my penis and reverse the habit?