It's not anything serious by now ...it is due to accidental tongue bite or exposure to extreme hot temperature .
Next Steps
Apply coconut oil .If it's pain ,then put Dologel ct ointment to avoid discomfort .Apply it for 5 to 7 min , then rinse ur mouth .don't swallow it .
Health Tips
It will take minimum 7 days to get better ..if not, then,consult the Doctor .