Persistent dull pain in frontneck area since start of feb. also productive cough after eating (but not due to acid reflux or postnasal drip). ideas?

Depends how long you: Have been coughing, and 6 weeks is a long time to be coughing. You may be experiencing food allergies, if it's always after eating, and not due to gerd, or pnd. You could have a sinusitis that needs to be treated before it gets worse, or you may be reacting to environmental allergens inhaled. So, go to your doctor, and have her/him check you out, and get your diagnosis soon.