I Had C 4,5 +6 Replaced March 16, 2015. I

I had C 4,5 +6 replaced March 16, 2015. I felt great at first, then slipped and fell, and also carried something's i shouldn't have, now have trouble pain in neck and shoulders, massive headaches, involuntary muscle movements when trying to relax or just being still, also have developed a stutter. What is going on?