During A Stressful Situation A Year Ago I Started Having

During a stressful situation a year ago I started having very painful episodes in my wrists, upper arms and shoulders. One resulted in a torn rotator cuff. The others have no diagnosis. I have been tested for autoimmune disease and arthritis - both came out negative. Since the stress has been relieved my episodes have lessened. Yesterday however both my upper arms became incredibly painful - unable to lift them - for no apparent reason. In the past if I immobilize the area it will get better after a couple of days. I have been prescribed muscle relaxers but they don't help. My gut feeling is that it's my tendons. These episodes are accompanied by crackling noises and feelings in the area also. I'd love to know what is going on, how to prevent it and how to ease the pain when it happens. It is debilitating.