I have the very very bad pain in the rotator cuff area of my right arm at the back, pain in my elbow on the same side, knots on my forearm of the same arm... I also have the same type of pain in my left rotator cuff from time to time. What can this be? I also have interstitial/fibrosis lung disease and was wondering if maybe this is all related? The pain is so bad I can't sleep at night. Thanks