First visit your dentist and have a clinical examination and check whether is there any ulcer... After examination only, the cause for the ulcer can be identified... If you have any medical problems kindly explain it to your Dentist...
Next Steps
Don't delay the treatment... Consult your Dentist as soon as possible.....
Health Tips
Avoid hot, spicy foods and even solid foods...
Consume more liquid foods,take fresh fruit juices and consume more water....