Headache, Sore Throat, Cough With Green Phlegm, Fever, Fatigue, Shortness Of Breath. Diagnosed Viral Illness

I ve had a headache , sore throat , heavy cough with dark yellow to light green phlegm coming up dizzy, fever (earlier in the week, but not now), I had chills associated with the sysmptoms but not now, troule concentrating, I m very hot and then shift to cold with out warning, heavy fatigue ( I slept like 16 hours today). I experienced shortness of breath today but things get better and then get worse it is like i am riding a rollercoaster with these symptoms. I went to the hopsital about 4 days ago and they told me that it was a viral illness and sent me home with ibrofphen it has now been 9 days total with the illness. Could it be more serious than viral illness?