That sounds really annoying that this happens and the tension you have sounds painful. Do you do stretching? If this is something like a nerve compression, stretching often really helps (as they recommend with things like sciatica). It will also help with your tension from sitting at your job. Drop your head down leading with your chin, move it right and left, look right and left, and many more types of stretches that help. Medical massage is amazing for the tension issue and perhaps the compression of a nerve would be relieved as well. I had many issues when I had to drive for hours at a time for work for an extended period of time. The stretching, massage and occasional ibuprofen did wonders. good luck
Hello~You definitely should see a chiropractor, all your symptoms point to misplace vertebrae and pinched nerves. He/she will take some x-rays of the neck and upper back, look them over and then discuss the results. After a few treatments, you should be on the road to recovery.