About 3 or 4 hours ago I started to have a sore throat with a headache and coughing. When I cough, it hurts my upper back and feel tired. Can someone tell me if this could be symptoms of the flu?

It could be symptoms of pneumonia. Go see a doctor.

You need to seek medical attention. It could be the cold or flu. Could be bronchitis or pneumonia. In the meantime, Mucinex every four hours and plenty of water should give a little relief.