Irritation on tip and sometimes in penis.

a little over a month ago i came down with a semi-severe sinus infection. I was placed on a 2 week prescription called avelox. Just prior to the symptoms and diagnosis, i had unprotected sex with a female. about 2 weeks after the intercourse and 1 week on avelox i started to notice strange seamen discharge. seamen was composed of an unblended mixture with two colors, bright white and almost a yellow, along with clumps. i first thought i may have contracted chlamydia. i got tested for chlamydia and gonorrhea and the came back negative. I decided to leave it alone. a couple weeks later i noticed an almost euphoric burning sensation during urination. i also started to notice a slight itch on the tip of my circumsized penis. after a single itch from my hand the irritation would be gone, however this could occur multiple times a day. occasionally i receive a similar feeling from inside the shaft. again, once i adjust it, the feeling is gone. i went back for a second STD test and again came back neg. my doctor gave me another prescription in case it was "bacteria in the urin". I have finished that antibiotic (ciprofloxacin) and had no improvement .

From what i've been reading it seems yeast infection could be a possibility. I am currently having to wait 2 weeks to see an urologist. Nevertheless, my sickness is on my penis and i worry about this constantly. In the meantime i'll be researching and trying to figure out whats wrong with me and possibly treat the problem. what other potential problems could be going on inside me?

thanks