Good luck with the surgery. I would not wish a shoulder injury on anyone. I pooped out on a heart stress test on a treadmill at my cardiologist office and almost fell off the treadmill when he would not shut the **** thing off. I tried to jump off the thing but failed and fell down on my right knee. I was barely hanging on with my right hand only and pulled my shoulder pretty bad. I had what they called a Frozen shoulder and had to get cortisone shots and then underwent physical therapy to fix a torn cartilage in my right shoulder.
Then a year later I got a adult 65+ flu shot in my left shoulder and got a bad reaction which made my left shoulder so sore I could barely move it. So I know what it's like to have sore shoulders.
Hang in there and best wishes for a successful operation and a full recovery.