A cough that keeps me up and wont go away!?

Hey i went to the doctors Saturday night and found out that i have bronchitis with developing pneumonia. He prescribed me Zithromax and that helped overall i have one day left of taking the anti-biotic and the last couple nights i cant sleep because i have a horrible cough that wont go away. I cant lay down because i cant breathe and when i lay down its constant coughing every 15 seconds, it almost feels like a tickle in my throat. I've tried Vick's vapor rub, turning a humidifier on, taking NyQuil and Nyquil and nothing seems to help. I've coughed so much the past couple days that my stomach is sore and tender. Any suggestions on what i should do? If this was part of the bronchitis shouldn't the antibiotics be helping by now? Any solutions or tips would be greatly appreciated, i hate not being able to breathe or sleep laying down. Thanks in advance!