Hi.. Thanks for the query.. Well the symptoms are pointing towards viral Infection that is leading to sores in mouth, inflamed gums and fever.. You might also have thrush which can be secondary to viral infections but the other symptoms are suggestive of viral infection only.. So it is advisable​ to consult an Oral Physician or Infectious disease specialist and get evaluated.. An oral swab culture and a blood test can be confirmatory.. You can be advised antiviral medication like Acyclovir along with topical application of antiviral ointment as well as numbing agents for relief. For Thrush gargling with antifungal mouthwash like Nystatin and Clotrimazole lozenges can help in resolving Thrush.. Also eat plenty of Probiotics like Yogurt.. Hope this helps.. Regards.