Smoking usually leads to white patches called leukoplakia or leukoedema. They occur due to nicotine in smoking which irritates your oral tissues. These patches can cause burning sensation or dull paining sometimes. You should get checked with a dentist to determine the exact diagnosis and treatment plan for the same.
Next Steps
First and foremost, quit smoking.
Visit a dentist or get consultation online.
Maintain your oral hygiene.
Reduce spicy food, alcohol.