Not to make you feel worse, but at this point, even tho' you are hurting, this part isn't so bad as, I am guessing, you have pain meds...yes? I found the start of therapy was worse since nothing stronger than over the counter pain meds then. Hang in there....it really will be soooooooo much better once you get the use of your arm back. When I had mine done, my step-son was playing college football. My goal was to be able to raise my arm high enough again to make that "touchdown" arm raise. It took a lot of perseverance and hard work, but I made it...and you will too.
Sounds like there are a few on here that have had rotator surgery done, so we understand what you are going thru'....so if you get frustrated, feel free to vent. We know what you are dealing with.
Healing hugs
Patti