Scm123, I also have significantly decreased penile sensitivity, so we both are trying to find a workout.
I am at nearly same age as you, however I have morbid obesity (about 180kg or 350lbs) which in turn means: very high estradiol!! But I'm not sure that it is the hormone to blame for my penile insensitivity.
Lab rats tests have shown that the chief hormone responsible for penile sensitivity is the dihydrotestosterone (DHT). The testosterone naturally converts ("reduces" in chemical terms) to DHT, but something might go wrong with the enzyme that converts it. So, DHT is available commercially as pills named Stanozol or Winstrol (I plan to try them soon).
Years ago, I had testicular infection that destroyed much of the testicular tissue, and the infection wasn't successfully treated because it was caused by the very resistant strain named MRSA. My testosterone plumeted downo 150, I could only (hadrly!) have some erections, without any penile sensitivity. When I started using testosterone enanthate each week, my testosterone levels now vary between 300 and 1100 along the week, and SOME of my penile sensitivity RECOVERED, say 50%.
To reach the normal penile sensitivity (as it was before my testicular disease), I sometimes eat pelnty of NUTS (pistachios are my favorites), and after that I feel great for a couple of days, my penile sensitivity recovers to 80-100%!
Unfortunately, altogether with the failure of my penile sensitivity, I also had orgasmic failure. Using testosterone enanthate shots and pistachios, I can feel 20% to 40% of the original intensity of my orgasm. There is a drug named "Mirapexin", developed for the treatment of Parkinson's disease, that is known to cause stronger orgasms; I tried that and worked for me, but is too expensive for my pocket (I live in a poor country) to use it on a daily basis.