Sometimes damage to the nerves of the scrotum caused by diabetic neuropathy. epididymitis, or inflammation of the testicles, caused by the STI chlamydia. gangrene, or the death of tissues, as a result of untreated testicular torsion or trauma. a hydrocele, which is characterized by swelling of the scrotum or varicocele may be the cause but without investigations we can't be sure. I would urge you to consult a competent urologist just to be safe than sorry. Thank you

Many reasons are there for such pain if u are not relieved with it in a day or two it's better go n meet doctor