I have had head congestion with runny nose, itchy watery eyes, my ears pop, and it feels like some mucus is building up in my esophagus. It s not constant, but happens in the morning, sometimes I ll sneeze at work because of the dirt and dust. I also have a cat. The clear mucus that builds up in my esophagus is bothersome, it makes me feel like I need to burp but can t. Why would this be happening?