Since 500 mg of paracetamol didn't provide relief, you can increase the dose to 1000 mg (two 500 mg tablets) every 4 to 6 hours, ensuring you do not exceed 4000 mg in 24 hours. Alternatively, you may take ibuprofen (400 mg) every 6 hours with food, provided you have no history of stomach ulcers, kidney issues, or asthma. Keep yourself well-hydrated and rest. If your fever remains very high, lasts more than three days, or is accompanied by severe symptoms like breathing difficulties, please consult a healthcare professional for a physical evaluation.