This is most likely a pinched nerve. You have a host of nerves that come out of the spine in that area. Obviously one of them is getting pinched and pissed off. Ice is not your friend here, when things get pinched they cause muscle to contract and the ice will only make it worse. Heating pad, anti-inflammatories and stretch the neck forward, chin on your chest, when the area is warm. Then stretch your arms across your chest to stretch out the trap area. Hopefully this will give you some relief.