Hi, I Hope You Can Answer My Questions. I Had

Hi, I hope you can answer my questions. I had back surgery in 2002, the doctor fuse a plate in the back of my neck because of some broken disc, i think it was c5,6,an 7, now i have been having some problems, with numness on my left side from my neck all the way to my feet. im in alot of pain all the time. some times the pain is so bad in my arm an left hand to where i havet to walk around holding it up. can you tell me whats going on ??