Any advice

Of course you know the first thing people are going to say, is go to the doctors. A lingering cough can be an indication of many things. If after two months you probably should get medical attention. My sister had a cough for a long time, I do not think she was congested though, and it turned out to be asthma. she had never had asthma before then. Allergies can sometimes be the cause of a cough, but you would need to know what you are alergic to .