Hi, Mouth ulcers are mainly due to stress and heating up of body than the usual. And one more reason could be
B12 deficiency. You can apply Dento gel every 3 hours which has anesthetic and antibiotic property. Thing is when the ulcers are less disturbed faster will be the recovery. You can take B12 supplements. Cap.Becosules once a day for 10 days, hydrate yourself properly and maintain good oral hygiene.
Next Steps
Let's wait for the reports too.