how long has it been since you did a fast? i have suffered on and off from similar problems due to a back upper back/lower neck. the thing that has helped me the most has always been juice fasting and bowel cleansing.
this type of problem is really caused by inflammation somewhere in the body impinging on nerves. fasting is the most affective anti-inflammatory i know of. whether its water fasting, juice fasting, The Master Cleanse or whatever. also important to keep the bowels moving during a fast.
how is your chiropractor? good? really good? you might want to look into finding a different one.
accupuncture is also very helpful for this situation.