Common Cold Supposedly Finished. A Few Days Later Lung Congestion,

Common cold supposedly finished. a few days later lung congestion, difficult and painful (right about sternum level) to fill the lungs even enough to get a productive cough. (yellow very salty mucus but mostly can only get it out first thing in the morning), fatigue, acute night chills, then sweats beginning about 4-5:00 in the morning. seemed improvement then relapses. two weeks now. Is this a 'wait it out' or a 'better do something'?