Billy,
I am right-handed and had surgery on my right shoulder January 29th this year. Of the four tendons that form the rotator cuff, the one in the back of my shoulder had torn off and one of my bicep muscle tendons was bad. The bicep muscle tendon had to be cut off at the shoulder and reattach to the bone below the shoulder. I was warned that the surgery would be painful, but I guess I was lucky. I was given a nerve block before surgery to stop pain, and it worked for two days. After that I was given hydrocodone, and it would work for 8 hours, but then I would feel like I had the flu. I quit taking the hydrocodone after two days and since then have had very little pain.
I went back to shooting two weeks ago. The rotator cuff tendon has not been painful or a problem, but the bicep muscle is still weak and somewhat of a surprise. The first time I shot my rifle I realized the muscle memory to work the lever was gone. I fumbled through it same as I did when I first started shooting. I shoot a Uberti 1873 and to do a reload I roll the rifle to the left, chicken wing style, and reload through the gate with my left hand. Before the surgery I could then lift the rifle with my right arm and bring my left arm up to the rifle as it came up. But now I can't get the rifle up with my right arm alone and have to wait until I get my left hand on the foregrip. Also, now there is no quick jerking the right pistol out of the holster, it just takes longer. If I try to go too fast the bicep muscle lets me know.
I am about halfway through rehab and will stick it out to the end. The first part was to regain and ensure movement of the shoulder and the remainder is to regain strength. I wish you well with your surgery. As other have said, do the rehab and you will get back to shooting soon enough. Hopefully your pain will be minimal as mine was.
Crusty Steve