I had a right shoulder rotator cuff tear repaired in 2011, 58 yo, along a with torn bicep and whatever the muscle is that runs along the clavicle. I am right handed, not really ambidextrous, but quite coordinated with the left arm/hand. That was a big help post surgery. Recovery was a long, and, at first, very painful. The first 6 weeks was absolutely miserable. Had to sleep sitting up in a chair, try to sleep anyway. Sometimes the painkillers, hydrocodone, would barely ease the pain. I was told by the PT that I should expect a lot of pain when first starting therapy, and take a pill before hand. IIRC, therapy was 6 months in office, and it took another 18 months, or so, for my shoulder to get back to somewhat pre-tear. The first time the therapist tried to raise my arm more than 90 degrees, I let out a bit of a scream and just wanted to stop. My shoulder is doing ok, almost 12 years post op, but never got back to total recovery. I still have issues with range of motion and doing any lifting of significant weight. Daily activities I am fine with. Everyone is different, and I am not trying to dissuade or alarm, just my experience. I have had 4 spinal surgeries, the shoulder recovery was worse than any of those.
Having said all of that, I wish you well, and suggest you do not try to push or hurry the recovery, do what the docs and therapists are asking you to do, but with the caveat, communicate any concerns you have with them. It is your shoulder and only you really know how it feels. If a stretch or exercise is more than you think you can, or should be doing, relay that and discuss the reasons for doing it, and options. They are the pro's, but truth in communication is important.