Get your doctor to prescribe "hycodan" cough syrup. This is a synthetic codiene cough syrup and will control the cough. It works very well for me.
I really feel for you getting sick at this time. Hang in there, it will get better. You may have to work feeling lousy, but then again, your new employer may not want you to expose them to the respiratory bug.
Be sure to get plenty of rest, very important.
If Z-Pak does not completely clear the bronchitis, ask doctor for a second round. I had to take 2 rounds. No need to half-way clear and then have a relapse. I waited 3 days before starting the second round and the relapse was worse than the first part of the illness.