Hi,Barry,
Welcome to HCM,
As your
HIV tests are negative after 7 months chances of having
STD is very less but by seeing your history and clinical picture you may require more sensitive STD test.
There is one possibility we should keep in mind that it may be a
plaque,a pre cancerous lesion on the tongue.
Consult oral surgeon and get
biopsy done to rule out any pathology.
Ok and bye.