Hi.. Thanks for the query.. Your symptoms are typical to viral infection only and the sores inside mouth are also due to viral infection.. You should consult a Physician and get evaluated so that he can do a mouth swab culture and a blood test for confirmation. In case if it is a viral infection then it commonly resolves once the virus completes its cycle in human body, however antiviral medications like Acyclovir can be advised.. Along with it take a combination of Ibuprofen and Acetaminophen and do warm saline gargles.. You can also gargle with Lidocaine containing mouthwash as it helps in reducing pain especially before meals.. Take non irritant foods and avoid acidic and spicy meals.. Take sufficient rest and keep sipping water... Hope this helps.. Regards.