What Causes Intermittent Fever Along With Constant Cough?

I have been to the doctors three times since dec 3, 2014. I have a fever that comes and goes, a bad cough for over a month now. I have been on z pack, levaquin, steroids (third pack) inhaler, and cough syrup. My chest and my lungs hurt so bad along with this bad cough and bad headache. I am a nurse.