Thank you for your query.
According to your symptoms, the most probable diagnosis is epydidimo-orgitis , an infection of the spermatic cord
and/or testis, this is not an STD
but a germ that reaches the area via the blood stream. In the absence of infection one should also consider a groin hernia
. Both require treatment but are not dangerous . The best doctor to see is a Urologist
. I trust you find this information helpful, please ask if any further questions arise. Kind regards.