Suggest Treatment For Nasal Congestion With Runny Nose

Hello - I have had a sever runny nose for about 3 years now. It has not really bothered me too bad except for coughing at night until November 2010. In December, due to the excessive post nasal drip I came down with pneumonia. I took a full z-pack course and the pneumonia has gone way. However, I still have the chronic runny nose, post nasal drip and sever coughing and chest congestion. Any ideas?