My whole left arm sore , tingling in left back for 2 months ( upper left of back) could it be bursitis ...the upper part of left arm hurts the most?

Arm pain: Most likely a trigger point which is like a partial charley horse in a muscle that sends referred pain down the arm.

Nerve irritation: When you get a tingly sensation, it is usually because a nerve is irritated. Although bursitis is a possibility, a pinched nerve in your neck can cause the same symptoms. See your primary care doc, and if necessary referral to a physiatrist. These symptoms usually improve with a short course of anti-inflammatories (if you can take them) and physical therapy.