As the others have said, it does sound like it could be a prostate infection or prostatitis. There are 2 kinds of prostatitis, one is definitely known to be caused by a bacterial infection, but there's another type where no bacteria or other infectious agents are found, yet the prostate is swollen & irritated. I would follow the Dr's orders for now, but just be aware that some types of prostatitis can be very difficult to get rid of, may take continued treatment for a few months. Good luck, hope you find a cure...
You do have a Prostate infection.. it could be BPH ( Benign prostatic hyperplasia) or Prostatitis.. Do you drink a lot of beers