I am amazed by how many folks here have had rotator cuff surgery. It has been 10 years since I had the surgery on my right shoulder. Although I am right handed, fortunately I shoot long guns left handed. If I recall, I used a sling for five days following surgery, then began the physical therapy. My surgeon firmly believes in PT as soon as possible. After surgery, I used a circulating ice water pump specifically designed for the shoulder. This device was part of the "surgical bill" and was given to me right after surgery. A truly incredible device. I had a group of amazing therapists and was very diligent in doing ALL of the therapy. Six weeks after surgery, I killed two longbeards with my 12ga. turkey gun (shooting left handed, of course). The Doc told me I would not be "able" to do so. That was sort of a challenge to me. At any rate, it took a bit over 12 months for a 100% recovery, but there was very little I could not do after the first 6 months. Fortunately, I have little memory of the pain associated with this surgery, but I do recall that the first several days were rather intense. Physical therapy was difficult at first, but got progressively easier (as it should).
Live everyone else has said, follow the instructions and do the PT without fail. I have seen the results of folks who did not perform the PT religiously and the results were not good. You get one chance at this. Do it right and you will have no regrets. Good luck to you, and be sure to keep us posted.