Pain is rather like a roof leak, you never really know where the leak is. Try using the alternate foot to operate your machine. I have begun driving with my right foot and sewing with my left. It has made a difference. Also, neck exercises, simply turning your head as far right, as far left, as far back and as far forward as you can comfortably do. Circling your shoulders, frontwards and backwards. the other suggestions have been very good too. We each are wonderfully unique people. Diff'rent strokes for diff'rent folks! Hope you find the answer.