I was reading a health book and ran across this paragraph "It is perfectly natural for the older man to respond more slowly to sexual impetus. If the slowing down of response results in a fear of performance, this fear itself can lead to impotence ..." This reminded me of my uncle, who stuttered, saying that the more he tried not to stutter, the more he did. He said that, before he started working through the book "Self Therapy for the Stutterer," he had instances of having to do some important speaking in front of a group where it was of utmost importance for him to speak professionally. That was the time that he was the worst ever, and he thought he would lose his job over it. Only having an understanding employer helped him save face (and job). He talked to his employer and it was agreed upon that he would give the information to another employee to present for him. The other employee would let the group know that he was only presenting the information and was not to get credit for the knowledge.
Uncle Kenny went to work on his speech therapy and was happy to eventually get to do the presentations himself. He realized that the fear of stuttering was the first thing he had to work on; once he was able to go into meetings and presentations without fearing that he would stutter, he was able to talk with less stuttering.