Hi, I've had a phlegm-y cough for about 2-3 weeks now. The mucus is clear and slightly neon yellow occasionally. Just this week I've had constant pain in my throat in the little indented area just above collar bone. My sinuses don't feel too congested. It's just this pain in throat & I'm coughing all day. I can feel the mucus & tickle in that area when I'm coughing. What is this? Thanks.