hello Thanks for query . Redness of the foreskin that you have is mostly due to rough anal sex. You need to take broad spectrum antibiotic like Cefotaxime along with anti inflammatory drug like Diclofenac twice daily along with topical antibiotic ointment like Neosporin twice daily. In view of it being a unprotected anal sex the possibilty of acquiring HIV can not be rule d out . Get basic screening test for HIV done to be rest assured about acquiring the same . Ensure to wash your genitals with warm water twice daily. Ensure to avoid sexual encounters till it heals up completely. Dr.patil.