Talk to General Physician on Undiagnosed Sickness

My father is facing utter weakness for a week. He was having 103 Temperature 5-6 oct which got fine in two days presently 97°F. He is a diabetic patient. He got tests done of CBC where platelets showed to be 25,000. I'm much worried. He also got lil bit of blood in vomiting. He is unable to eat and feels very weak. He also complains pain in abdomen. Kindly guide us if its dengue or something else.