It will heal and get better in few days time. Nothing to worry about.
If the ulcer persists for more than 8 to 10 days then consult your dentist.
Next Steps
If causing pain and discomfort while daily actions of speech and eating,you can apply gel like dentogel, dologel ct or mucopain gel on the affected area 3 to 4 times daily..
Health Tips
Avoid eating spicy and hot food from the affected side.