Hi there...viral fevers can present with sinusitis and generalised body weakness. Sometimes they can even cause joints pain. Headache could be due to sinusitis. Viral infections usually take a few weeks to recover from. Kindly consult a general physician. After examination and few blood tests, they will able to start you on prophylactic antibiotics, antihistamines, antipyretic. At home take complete bed rest and have plenty of fluids.