Thanks for your query,based on the facts that you have posted it appears that you have ring worm infection
of the skin around thigh and scrotum.
Please take anti fungal medication
twice daily along with topical anti fungal cream for local application over affected area .
Ensure to wash the area with warm water before applying cream.
Wash your inner wares in boiling hot water mixed with antiseptic lotion like Dettol.
This should get cured within a week,
As regards swelling iabove the testicle it a a benign spermatic cyst
and it has no significance