I have the exact same problem. I am currently 41 years old. My problems started in 2001. I have never had any STDs. Never had problems before then, suddenly I couldn't get an erection, but I could still have an orgasm. Starting in 2004 I starting have pain whenever I had an orgasm, same location as stated in the previous post, a couple of inches right below the belly-button in the center. Pain level similar to a leg cramp. The pain would last the length of the orgasm. Then, for about 15 minutes after that, I would continue to feel like I need to have an orgasm. Also during this time, semem would slowly drain out. Also starting in 2004, I started to have problems having an orgasm with only achieving this about 70% of the time. Starting around 2011, I have started to gget a partial erection, but nothing like prior to 2001. The partial erections would happen about 40% of the time, rest of the times I would have nothing. Also since 2004, after having an orgasm, I would hhave problems breathing, feel agitated, I would feel I have just had a large amount of caffiene. Very restless.
I saw a urologist in 2004 when the pain started. He stuck a camera up inside of me and checked my urinary track, bladder, and prostrate, but didn't find any problems. I also had a CAT-Scan done and couldn't find any problems. Since then I have talked with various doctors that I have seen for annual checkups, but they either didn't have any idea about the problem or didn't care and wanted to change the subject to something else. Currently I haven't found any doctor that has any idea of the problem. I till only get partial erections about 40% of the time, the rest nothing, and orgasms about 50% of the times. Also, as far as sensitivity, sometimes it hurts when I have an orgasm in the urinary tract. Also, I don't feel much from touch or any physical contact.
Any ideas.