Thanks for the thanks about the forum.
The only reasonable conclusion is that you have no STD and never did. STDs from oral sex are uncommon; no STD can cause symptoms 'the next morning'; every STD that exists takes at least 36-48 hours before symptoms begin. The only possibilities for urethral pain or 'pinched feeling' the next morning are physical or chemical irritation (e.g., from spermicide, irritating vaginal perfume, latex allergy, etc) or anxiety, which can markedly magnify otherwise normal body sensations. The lack of disease on testing further prove you have nothing, and in any case the antibiotics you have had would have cured anything that somehow was missed by the tests. I see no reason not to resume unprotected sex with your wife.
See this thread from a few days ago, which probably applies to you:
http://www.medhelp.org/forums/STD/messages/4153.html.
Good luck-- HHH, MD