What Causes Recurrent Neck Muscle Pain?

65 YR OLD FEMALE- PINCH NERVE OR MUSCLE PAIN BACK OF NECK- BUT ALSO HAVE SWELLING IN FRONT ALL ALONG COLLAR BONE LUMPY SOFT EGG SHAPED PLACES- 1ST TIME IT CAME (APRX 2 WKS AGO) SEVERE BURNING PAIN ON COLLAR BONE- PAIN CAME AND WENT FAST BUT SWELLING STAYED AND SLOWLY STARTED TO GO DOWN- NOW IS BACK (BUT W/OUT PAIN ON BONE THIS TIME) SWELLING SEEMS TO BE INCREASING. THANK YOU FOR HELP