I had a vasectomy when I was about 39 and did very well with great sensation and stamina until...I was about 49 and definitely was noticing changes in erectile strength and endurance. By the time Viagra hit the market, it was a godsend but I noticed that using it was different than with no meds in my system. Over the last 5 years I have appreciably lost orgasmic sensation. Otherwise, we have -over a period of 25 years - created an exciting and rewarding sex life. I particularly love watching her being pleasured by another (stronger) man and she has several lovers (a couple of 'old friends' before we married) whom she sees occasionally..either in our threesome mode or by herself and later narrating the details to me. Such episodes tend to cause me a great excitement and increased sensation and endurance..sometimes without Viagra! Still, I'm nearly 67 and my pleasures with her are becoming more subtle and often voyeuristic and vicarious. This seems to have a naturalness and sense of progression. On another plus side, my wife works out nearly every day and looks terrific at age 65! She also loves being able to have male friends and lovers with diverse qualities Our love is very deep and we feel very privileged to have achieved this degree of trust and intimacy. I just wish I was the man I was 30 years ago... :=} It's still about learning to make a better lemonade...
I have had a similar experience. I had a vasectomy in 1993 at age 42. I was told to wait 30 days before having sex with my wife or masturbating. When I resumed sexual activity, I had a much reduced sensation in my penis and difficulting in achieving orgasm. I went back and complained to my urologist and he told me to see a psychiatrist. I went back to my General Practitioner, whose medical school buddy was a psychiatrist at a teaching hospital, and learned that there was a small but steady stream of people just like me ... none of whom were being treated successfully by psychiatry. With the growth of the internet, and chat rooms, I have talked to dozens of people with reduced penile sensation following a vasectomy.
At this point, there is little understanding of what is going on to cause this phenomenon. There is speculation that it is tied to an autoimmune response to the semen, which is going someplace it really shouldn't go. (Semen, I have read, is highly allergenic ... and I certainly have plenty of allergies.)
At this point, you have to come up with coping strategies. You need to schedule sex when you are not tired, use Viagra or other ED medications, and indulge in activities with your wife that are a particular turn-on.
I have discussed vasectomy reversal with several doctors, but they are leery of making a bad situation worse. If the autoimmune response has done nerve damage (which they suspect) then reversing the vasectomy may not do any good. Or maybe it might. But as my doctor asked me, "Do you want to be the first one to try?"
The one really good piece of advice I have for you is to print off a copy of this correspondence and show it to your wife. Both of you need to understand that this problem has nothing to do with your state of mind.