What Causes Persistent Cough Along With Tightness In Chest During Nights?

I have been sick for a month now. Been to a doc 3 times. I was told I have sinusitis. I am on my second antibiotic and all symptoms seem to be improving except at night I cough the entire night a horrible sounding cough like with croup. Accompanied by severe tightness in my chest and wheezing. What is causing this I am so miserable and need relief and sleep!