What Causes Pressure On The Sides Of The Neck?

I have this pressure on the sides of my neck, and it happens often, but goes and come. It is not muscle pain, but it occurs at the same time that I feel this bubble in my chest followed by a sharp pain, sometimes I even feel like my stomach is moving, it is awful... on the right side of neck in particular, I feel like a very sudden pulse, movement, but it seems to be all connected, neck and chest (or stomach?) pain... My doctor wanted to send me for a MRI, and the insurance company denied it based on not having any treatment prior, but I just started having this problem around the middle of october... it seems to be getting worse and more often... then my doctor wanted to send me to an ENT, I don t see the connection, I have been diagnosed with acid reflux, and he gave me medication for that, but it is not helping these other symptoms... It really started to worry me...