Rx:

beer 1 tin
steak 400 g
sig: take 1 tin of beer and steak each night





ok jokes apart..........chance is quite low (except number 7).......
as for the symptoms.......i believe my prescription above will help you get some good sleep and rest your mind

if symptoms (broken gum today [嘴破], a little cough and sore throat) persist........go consult a doctor....

by the way.....it will be helpful to post the closeup picture of the broken gum just in case it might be a primary lesion of STD

not positive

unlikely HIV

anyway, no harm getting yourself tested

0 if tested and clean, assuming the result is correct.
more than zero if never tested before.