Hi.. Thanks for the query.. It looks like you either have canker sores or apthous ulcers or it can also be due to viral infection causing herpetic cold sores.. Nothing to worry, as either of them are treatable and will resolve in a period of one to two weeks.. As of now start taking a Vitamin B complex tablet daily along with lysine and folic acid .. Gargle with mouthwash containing Lignocaine or Lidocaine to reduce burning especially before meals.. You can also do soda bicarb gargles, warm saline gargles are also helpful.. Suck ice pops or do cool water rinses.. Take soft and bland meals.. If you get relieved in a week its fine or else get an oral swab culture and blood test done for herpes and then if it comes positive antiviral medication can be advised.. Hope this helps.. Regards .