I Have Had This Cough For The Past Few Months

I have had this cough for the past few months now, and it will not go away. It mainly happens when I lay down, or in the morning when I get up. It gets so bad at times, I actually throw up. I need help with this. My doctor wouldn't even look into it. He told me to suck on a cough drop. When I went to the hospital a few weeks ago, they said it could be a form of asthma.