hellooo...read thru ur query...i must say that it might be swollen due to local trauma while eating or some candidial infection...and while using listerine u should dilute with water and use otherwise it can cause burning..cause depapillation and inflammation of the tonsil in some cases...but dont worry...u can brush twice daily...scrape ur tongue with tongue scraper(can reduce the load of microbes inhabiting and cause various tonsil infections)..use mouthrinse(diluted).do salt water gargle(increase healing process)..apply nystatin gel on the tongue to reduce fungal infectiondo this for a week or so and still not reducing meet a dentist and get the treatment based on the clinical situation...be happy and cool(thats the best way of treatment)..hope ur benefitted something with this reply..have a healthy day!!!