Thanks for your query.Based on the facts that you have posted it appears that you have
infection of foreskin (Posthatitis)mostly due to Oral sex
There is nothing to worry about If your foreskin can be retracted over glans penis
The infection of the foreskin can be combated by taking antibiotics like Tetracycline
twice daily along with antibiotic ointment like Neosporin
for a week.
Get the prescription of these drugs from your family Physician.
Please clean the genitals with warm water twice daily.
Avoid sexual activity ti it heals up completely.