Hi , I know I am late but ..... Thought of putting my point of view also ....May be because of third molars as it's in that area
It can be because of stress .. Because of exams or any other tension
Next Steps
you can have SM fibro ,once daily for 1 wk
apply turbo Cort gel over the area
first thing show to a dentist for his/ her expert opinion
Health Tips
Take life as it comes 😉, take less stress as u said u often get ulcers
Best of luck