As far as I know, a trapped in nerve in your neck wouldn't cause buzzing or anything in your feet - mostly that would be affected by your lumbar spine. BUT I do know that buzzing and twitching is a VERY, VERY common symptom of anxiety. I have had an insane number of unexplainable physical symptoms actually confirmed (as far as I and my doctor can tell) to be caused by anxiety. Had about every blood test known to man and everything always checked out fine. So all this to say, I doubt your neck is the cause but I honestly would not worry about a symptom like that. I can almost guarantee it's anxiety.