CP (Chronic Prostatitis) or CE (Chronic Epididymitis)?

I'm having constant dull pain in my left testicle for nearly a year now. I'm very confused what is causing the pain, whether it is CP or CE.

I took all the tests asked by my urologist. No STDs found, semen, blood cultures are normal, and PSA levels are normal. Except one time, it did not hurt much during finger technique in anus to see whether prostate is swollen.

Testicles are looking normal in the scrotal ultrasound, however there was mild swelling on left inguinal region.

My urologist is unable to conclude whether it is CP or CE.

Here is my symptoms:

- Never had fever or chills anytime before or after the pain started.
- The pain is constant and dull, which means the pain is there even when I don't touch.
- I have tenderness to touch the chords (nerves) in between testicle and prostate.
- No visible changes seen from outside the testicles.
- Pain on left knee, left leg and left feet as well.
- No burning during urination, and the frequency is very normal.

Can anyone say whether it is CP or CE or something else?