That was my first thought, after trying everything else and have the side effects become unbearable, actually looked at a prosthesis procedure. The Urologist prescribe trimix and I tried it. When considering the lack of side effects, quick response, and the ease of administration, the needle to the dick, isn't even a thing. I copied from my dentist that he would ever so slightly vibrate the needle or flesh when inserting to trick the senses. That made the injections even more bearable.
Mine runs about $80 for enough to do 10-15 injections.