I had rotor cuff problems before my illness started. It was not a tear, but an impingement with a lot of pain and inability to use my left arm for much of anything. It made the rest of this harder because I could not use a walker to help walking because my right arm was the only part that really worked. I got range of motion back with a lot of physical therapy, but still cannot use the left arm for much, but now I can at least stear the walker with the left arm using the right one as the power arm. Having two arms keeps me from just going round and round in circles!!! For you, with a tear, you probably cannot do much with that arm and may be continuing to cause damage with trying to use it to get up. This might be contributing to a delay in healing. My tiny suggestion to think about is using a cane (perhaps one with the four stabilizing feet) on your strong side to help you get up without having to stress the side with the tear, but still not fall. If you find you can do this, maybe the side with the rotator cuff tear can heal or maybe you would feel better about not being stuck in a bed or chair if you were to have surgery.
WithHope for a cure of these diseases.