Hi, thanks for your question. Sometimes the tonsils take a long time to return to their normal size after an infection and sometimes they stay enlarged without causing any problems.
Tonsil stones, or tonsilloliths, are formed when trapped debris hardens, or calcifies in the crevices of the normal tonsil tissue. This tends to happen most often in people who have chronic inflammation in their tonsils from repeated bouts of tonsillitis. I am not able to tell if this is what is causing the white spots on your tonsil.
It sounds like you have already been to see your doctor about your concerns re STI’s and your tonsils. I would suggest seeing them again if you are concerned about any further symptoms. Health Nurse