hello and welcome to hcm,
first of all i would like to mention that, you have mentioned your problem very haphazardly(please don't get offended). secondly, visit the dentist
assoon as possible. if the condition was lichen planus
had been done, then probably the reaction can be because of extra tissue pulled from the area, which had caused some ill feeling. lichen planus can be due to viral cause or by genetic effect as well.
chlorohexidine is helpful undoubtedly, do it for 2 times and for 10 days only if the condition subsides.
take the help of ENT specialist
rest please define the problem sequentially, and then we will see.