What Does White Spot On The Penis Head Indicate?

Hi i got a problem about my penis its got a white spot in the head and body of my penis and redness also i tried several antibiotic but it doesnt work. Amoxcillin and cefixime tablet for 3 days now worst the white little circle got too many already. I never have any history of multiple partner. I only have sex with my wife. Please help thanks. Now i have doubt that my wife she got other affair.