Stunner from the symptoms that you have described it sounds like you may have what is called prostatitis or a fancy name indicating inflammation of the prostate. These symptoms are not associated with AAS use in any way. First off AAS use causes what is called BPH or benign prostatic hyperplasia. A big word that means enlargement of the prostate gland. This occurs over time to almost all males as we age from the conversion of testosterone to DHT.
steroid users may have symptoms occur early in life than others. Symptoms result from the enlargement of the prostate which puts pressure on the detrusser muscle of the bladder which causes symptoms of urinary hesitancy, weekend urinary stream, feeling of incomplete voiding after urinating, and urinary frequency. None of these symptoms are what you are experiencing. Prostatitis most commonly occurs from a bacteria infection that originates from the urethra. It travels upward to the prostate and causes an infection. Other causes are from retrograde ejaculation. Your story from what you describe fits the retrograde ejaculation etiology. Where urine after traveling from the bladder to the urethra is flowing back up an into the prostate ducts (perhaps this why you are not ejaculating). Factors that contribute to prostatitis are male sex, urinary tract infection, trauma, dehydration, and in sexually active young men. Symptoms can include painful and little ejaculation, low back pain, increased frequency to go to the bathroom, painful urination, scrotal pain and penile pain. It sounds like your doctor thinks it caused from a bacterial origin hence the prescription of antibiotics. Prostatitis are stubborn infections and need to be treated for 4-6 weeks. If no improvement after antibiotic therapy you are left with a structural problem which will require further testing will(voiding tests, cystogram to visualize the urethra). Rest assured most cases are bacteria and symptoms subside after 2 weeks of antibiotic treatment. Definitely does not sound like BPH or prostate cancer. These two are extremely rare in individuals less than 50 years old.