Maybe be due to throat infection...Drink plenty of water,eat soft foods like cooked cereal, mashed potatoes, soft fruits, yogurt and soft-cooked eggs...give adequate rest to your body..Avoid spicy foods or acidic foods... Gargle with warm salt water. gargling several times a day can help relieve throat pain....you will require antibiotics to clear up infection..Consult ent specialist once for examination they will do the needful.