When I swallow, I have a clicking sound/feeling under my chin. What could this be from? I have had a chronic cough for over a year.

Chronic cough. You should be evaluated by your doctor for your cough. The "clicking sound" is an unusual symptoms but an ENT doc may be of help. If you lost lots of weight due to the chronic cough, it could cause your voice box to "click" as it moves up and down over the vertebral column behind it.