Welcome to HCM.
Due to masturbation
one will not get strain over the pubo-coccyges muscle that too lasts for 5 years. It could be due to Prostitis only as your Physician told. This can be confirmed by per rectal examination
, prostatitic massage following examination of prostatic fluids and culture and sensitivity test from the massage fluid.
If it is not found evidence for prostatitis
then you have a ultrasound
examination of abdomen and pelvis and if needed an MRI examination. That will fix your problem and on which the treatment can be planned.
Wish you a speedy recovery.