Thanks for your query.Based on the facts that you have posted it appears that you have infection of glans
of your penis ( Ballanitis).
Since you have no urinary symptoms or symptoms like itching ,discharge etc you should not worry at all.
This could be due to contamination of glans with cloths (inner wares).
Please take broad spectrum antibiotics along with anti inflammatory medication like Diclofenac
twice daily .
Get the prescription of medicines from your family Physician.
Ensure to clean your genitals with warm water twice daily.
Avoid using tight cloths.