Hi, do you still have persistent throat pain or difficulty swallowing? are there any palpable nodes in the neck? if present it could indicate that there is persisting infection. White patches are common in many throat infections. The sore throat and tonsillitis which you had may have contributed to it. In response to the infection the body produces soft white debris which collects in the tiny indentations in the tonsils called crypts. Repeated salt water gargles will help. Mix one teaspoon of salt in 1 cup of warm water and gargle. If the patches increase in size or become painful then consult your doctor. Regards.