Question regarding complete reverse shoulder replacement

On May 7 2025-I underwent a complete total shoulder replacement on my right side. There were complications following the surgery, including the fact that they put me in a shorter splint than my arm. However, I have been discharged from occupational therapy even though I still do not have full use of my right hand. They are telling me that it may take six months to a year before I regain full use of my right hand. This is frustrating for me because before the surgery I had full use of my right hand. The biggest drawback of the way that my hand is now is I cannot drive. I haven't driven now for two years due to the pain in my shoulder. Which has nothing to do with my hand. They keep insisting it's arthritis. I have argued with them that this has nothing to do with arthritis. It even hurts when I wash my hand. I am just wondering if anyone else has gone through anything like this.