What Is The Treatment For Headache , Fever And Sore Throat?

I HAVE A 10 YEAR OLD BOY - 2 WEEKS OF FEELING VERY POOR. STARTED WITH JSTU REGULAR COLD SYMPTOMS: HEADACHED, RUNNY NOSE, SORE THROAT ADN LETHARGY. AT 9 DAYS IN NO REAL IMPROVEMENT. WENT TO PEDIATRICIAN... RAPID TEST FOR STREP NEGATIVE- SUSPECTED SINUS INFECTION DUE TO PERSISTANT HEADACHE AND GAVE HIM AUGMENTIN - SOME IMPROVEMENT BUT BACK SLIDE AGAIN YESTERDAY AND TODAY. NO REAL ANSWERS FOR STOMACH PAIN AND LETHARGY. HE STILL IS FEELING VERY POOR AT 14 DAYS OF THIS. EXTREME LETHARGY, STOMACH ACHE AND HEADACHE ARE HIS MAIN COMPLAINTS. HE IS PAIL, DARK CIRCLES UNDER HIS EYES, NO APPETITE AND GENERALLY AND NOT HIMSELF. CAN THIS TRULY BE A VIRUS LASTING THIS LONG OR SHOUDL I BE CONSIDERING OTHER OPTIONS.