Hi.. Thanks for the query.. It looks like you have inflammation inside mouth.. Due to inflammation you are experiencing pain and soreness.. Inflammation and soreness can be due to numerous causes but common ones are allergy to certain foods or chemicals, deficiency of or or vitamin B 12 or both, burning the inside of mouth while eating something very hot or irritation with any chemical substances or mouthwash etc.. Fungal infection can be another cause.. So first of all consult an Oral Physician and get the cause ruled out.. Treatment of the same will help in relieving the oral symptoms too.. For now symptoms can be managed with gargling with numbing mouthwash containing Lignocaine like Magic Mouthwash.. Start taking Vitamin B complex supplements daily. You can also do cool water rinses and suck ice as both of these can absorb heat and reduce inflammation.. Avoid hot, acidic and spicy foods.. Hope this helps.. Regards..