Is it bronchitis or something serious?

I started getting real sick a few days ago, I had a sudden high fever, chills, coughin up mucus, chest pain the whole nine yards. I think it was a day flu. I feel much better now but Im still coughing up mucus, when I cough u can hear the congestion in my chest and it doesnt seem like its getting any better, and I also have shortness of breath when Im laying down, sometimes while im sittin up too. I have to take deep breaths like I have asthma. What could it be and should I go see a doctor?