Congestion, Constant Coughing, Prednisone, Doxycycline, Nausea, Shortness Of Breath, Tiredness. Reason?

Over the past 3 weeks I have been increasingly getting sicker and sicker. A family doctor put me on Zithromax and a codeine cough syrup for my major congestion and constant coughing... Nothin helped and a week or so later I was prescribed prednisone and doxycycline . The doxycycline made me so nauseous I would throw up within a half hr of taking it so I stopped. I have been super nauseous, getting major headaches, and coughing constantly to the point that I have both major headaches and I am constantly throwing up. My chest is super sore and it is getting really hard to breath. I took a breath test a few days ago and scored 620/1000... Even after a breathing treatment. It s gotten worse since then. Now I can hardley breath at times, my muscles are sore and I feel super tired in instances where I shouldn t be (climbing stairs) and completely out off breath. Also, my heart rate has been over 100 for almost 2 days now... Fast enough that I can t sleep now. Thoughts?