Okay, so you kissed with a mask? Then how did you exchange saliva?
There is no risk here. Kissing doesn't transmit STDs, especially with a mask, and a very brief lick of your scrotum won't either. The skin on your scrotum is too thick.
I don't know why you are having these symptoms - anxiety, allergy, stress? - but see your doctor. They are not STD symptoms.