I have a sore throat, I have been feeling a bit dizzy and tired over the past few days?

About three days ago, I started having a sore throat, I started guessing I would probably go under a flu. But then I never had any nose congestion or coughing. I only feel dizzy and extenuated when I wake up and that feeling goes on for the whole day. I am not experiencing any loss of appetite, eating does relieve a little bit, including vitamins, except the relief doesn't last. What should I do?