Here is from the Merck manual, if you have not already seen it:
Epididymitis is inflammation of the coiled tube on top of the testis in which sperm mature. Epididymitis is the most common cause of scrotal pain in adults. Epididymitis is usually caused by an infection, typically a sexually transmitted one. However, sometimes there is no infection. In such cases, doctors believe the epididymis becomes inflamed by reverse flow of urine into the epididymis, perhaps because of straining (as when people lift something heavy).
Less common causes
There are a number of less common causes. Less common causes include
A hernia in the groin (inguinal hernia)
Infection of the testis (orchitis), usually caused by mumps or another virus
Pain from a disorder in the abdomen (such as a kidney stone or appendicitis)
Injury
Other options:
Assuming it's the ph of the urine -- try drinking cranberry juice every day
Assuming it's a physical issue they haven't caught -- get an abdominal MRI (that is the gold standard for soft tissue imaging, other scans are just not as good)
Assuming it's anxiety -- go see a therapist about your anxiety. If you are generally anxious anyway, this is not a bad idea for your mental health overall
I have had it checked many times by a few urologist everyone says there’s nothing wrong with me
Please get your prostate checked.