Sir, You need to be examined for proper diagnosis and treatment. There are so many causes for raise in neutrophils. You should be properly investigated.

Hello,mouth ulcer could be due to metabolic disturbance, trauma , hot food items, vitamin deficiencies etc.. Have buttermilk , curd ,tender coconut , apply local anesthestic gell ,take vitamin B syrup. High neutrophil count says it could be bacterial infection .And you have on and off fever to support it. You may need antibiotics consult general physician.