I’m a 24 year old man who 7 months ago performed oral sex on another man and swallowed. 2 days after I had a cough and felt a bit fatigue, but it only lasted for 2 days. I noticed my tongue starting to turn white and since then it has gradually got worse to the point where my tongue is covered white and I can’t scrape it off. I’m worried this is due to an STD. Do you have any idea why this is? I tested negative for hiv on a oraquick test at 3 months post exposure and 4 months. 

Welcome to the Forum.  Thanks for your questions.  I'll be glad to comment.  The exposure you describe was very low risk.  Acquistion of STIs, including HIV following performance of oral sex on someone are very uncommon. Your Oraquick test is strong evidence that you were not infected with HIV.  Falsely negative tests at 3 months following an exposure are very, very rare.  Your white tongue is non-specific and almost certainly NOT an indicator or HIV, no matter what sort of misinformation you may have seen on the internet.  There are no STIs which would explain your white tongue.  One common cause of white tongue is smoking.   ---

I did see my doctor but they didnt know what it was, I done a routine blood check (never told them about sexual encounter) and it all came back fine. I have had severe depression over this for months now and guilt about the encounter, because the white tongue started to appear days after, do you think it’s purely coincidence? 

I am confident that the discoloration of your tongue is not an STI, nor is it thrush ( your doctor would have recognized thrush).  If, after knowing that it is not HIV or another STI, you remain concerned, you could see a dermatologist or perhaps your dentist.  EWH---