What Causes Difficulty In Emptying The Bladder Completely Post Surgery For Testicular Pain?

Hi I had surgery on my testicle for chronic testicular pain and they also took out a varicose vein the surgery was something called spermocosis or something but after the testicle pain left I now feel like there's urine in my penis 24/7 and I can keep peeing and peeing and itS still there I can see it in the opening there is urine that just won't come out and ito really annoying and sometimes a little painful do uk what it is?