Why does it get harder to breathe?

I have a cold and my cough is not dry. Does it mean I have bronchitis? I have difficulty breathing right now. So I cough and it helps, but a few seconds later it's worse. It keeps getting worse. Drinking water with suger also helps for a while, but then I get worse. Why? I had this as a child and my doctor said I had asthmatic bronchitis. But I thought it was gone now.