It definitely sounds more like prostatitis, you are correct, but I'm not at all clear that doxycycline is the drug of choice for this condition. Often clinicians use one of the quinolone drugs for this condition, for weeks at a time.
You have had quite a few sex partners in the past few months, and although I don't think the bumps sound like herpes, I think a herpes antibody test would be a good idea. I also think you should take with our health care provider about the choice of antibiotics for the prostate issues, if he thinks they are still going on. Remember when you get a herpes antibody test, you want an IgG test, not IgM. You mention you are STD negative, but I"m not sure if that includes herpes testing, does it?
Terri
I had simular symptoms to yours (see my post Urethral Herpes?) and after greater than a year since my last "suspect" sexual encounter, I have still tested negative for HSV-1 and 2 via the Western Blot test (most accurate).
I had little bumps like you describe, but it was most likely a combination of fordyce spots and over anxiety.
Your symptoms sound like text book CPPS (Chronic Pelvic Pain Syndrome) aka, non-bacterial prostatitis.
There is a book called "A headache in the Pelvis" that goes into detail, but to sum up, anxiety over genital concerns (STD's) can cause great tension in the inner muscles that results in incontinence, dripping, painful ejaculation, a burning tip in the penis, lower back pain etc.
I've gone to Physical Therapy for it and it was just about gone until I took an HSV test at 12 months and popped a false positive for HSV-2.
My status was confirmed HSV-1 and 2 negative via the western blot, but even when I recently came down with an episode of jock itch, I was concerned it must be herpes.
I would ask your urologist if he can refer you to a physical therapist that threats CPPS.
It's done wonders for my condition, hopefully it can help you as well.
With all this said, I agree with Terri and get the IGG done just to be sure. Just realize there are false positives that occur pretty frequently, so don't freak if it comes back with a low positive.
Cheers,
Borat