Why am i fealing pain on neck around the region of my collar bone whrn im swallowing or breath with my mouth. Also, whrn im not swallowing, it feels sore and a bit enclosed. And when i breath in deeply, i have this pinching pain in my chest. If its of any importance, this stattef right when i stsrted chewing gum. I havnt had an allergy to it all my life, though im not excluding that possibily