Thanks for your query.Based on the facts that you have posted it appears that you have developed Balano Posthatitis due to oral sex
Though you do not have vaginal sex possibility of getting STD
with oral sex can not be ruled out. Get your blood tests for STD done to rule out the same..
Take some antibiotics like Augmentin
along with some anti inflammatory medication like Diclofenac
twice daily for a week.
Avoid sexual encounter till it gets cured completely.