Thanks for your query . based on the facts that you have posted it appears that you have what is called as Infected Sebaceous cyst
.This is due to accumulation of sebum secreted by sebaceous grands located in large numbers in scrotal skin.
However final diagnosis can be confirmed only on clinical examination .
Consult qualified Surgeon for examination He may advise you to take some antibiotics and get it excised in Toto under local anaesthesia.