By what process have the uro's determined it's non-bacterial (most
prostatitis is non bacterial).  I would hope they at least did an expressed
secretion and looked at it under the microscope (and also looked at at your
urine sample under the microscope), and did they also culture your expressed
secretion (probably not unless you asked them to), or did they just do the
dipstick test in your urine sample - which is useless.  If it is non
bacterial it is a son of a bitch to live with and you should ejaculate as
often as you can to prevent infection in all the little acini's.  Try
soaking in hot water also for theraputic relief.  And you may want to ask
for an antibiotic like levaquin (just to see if it helps for a low order
infection that may not be showing up).  The microbials in the prostate are
hard to get to.  If they saw white blood cells under the microscope but no
pus or bacteria, I would ask for the anti's anyway.  Uro's used to hand out
cipro and bactrim like water even without a confirmed bacterial analysis.  I
have suffered many times in my life (24/7) with prostatitis (mostly non
bacterial).  Try to ejaculate at least once per week and soak.  It doesn't
sound like you are having a lot of discomfort.

Good luck...Pete