seems like what you have is Chronic pelvic Pain Syndrome
. your doctors have tried to treat you correctly. this disease tends to be chronic and occasionally needs more aggressive treatment.
one of the key components in treatment is to regularly release semen to de-congest the prostate. you may also be commenced on an alpha blocker
under medical supervision which will help you pass urine better and also reduce the residual urine you are mentioning about. if you are seemingly not better even with all these measures after 3 months, we could consider further evaluation with urodynamic studies and cystoscopy
by a good urologist
Do not worry. what you have is a chronic disease and not a life threatening one.
With Best Wishes,