Heart Palpitations, Tender Neck, Painful Breathing, Brown Mucus

I went to the doctor 10 days ago. I had a upper respitory infection that became unbearable. It hurt to breathe and I had shortness of breathe(it lasted for a month and a half and I decided I needed help). I was put on Prednisone for 6 days (60mg, then 40 mg then 20 mg intervals), xopenex nebulizer , and Doxycycline antibodic. I am redeveloping symptoms. I had heart palputations a few days ago, they are still happening but not as often, my neck is tender again, when I breathe deeply it hurts into the back of my neck and top of my head and my lungs still hurt. I quit smoking a month ago, through all of this not a lot of mucus has come up, when it does it is a deep brown( not a lot at all). I just want to feel better!!!!!!!! I am 34 yrs old, female, and 230 lbs(TRYING to lose weight, the prednisone DID NOT help).