Men's health problems

I am in the 60 and have been married for more than 35 years. In the first years of our marriage, I have always been hard whenever I wanted and my wife has never had to do anything for me awake. Accordingly, it has never attracted me, and practiced hard. We used to play our preliminary sex, and I am usually trying to get to the point where it can have an orgasm. When you use one of the drugs to get an erection, there must be some stimulation in order to make it work. Unfortunately, it is unable to stimulate me satisfactorily to get pretty hard. Even performing oral sex on me not to. Part of this effect, it does not do is a fear that I ejaculate in her mouth. The whole thing is very frustrating and I do not know what to do.