Readers Digest version.
Was seriously hurt at work.
Both shoulders and left elbow had surgery done in June 2016 and October 2016. Even had bicep muscles cut, moved, and re-anchored and attached into the bones.
With lots of Physical Therapy, I retained most of my original range of motion.
Began using dumbbell weights for a few months.
Then slowly began exercising my arm/back muscles using a very light bow.
I was practicing with my 45# longbow in the back yard.
But, I will not be able to bow.hunt this season, due to not being accurate enough to take game cleanly out to 20 yards (60 feet).
With proper practice at a slow pace, I should be back into the game.
My advice would be to get the surgery done.
Cortisone injections will not be a proper long term solution for your needs.
Most times the cortisone injection, is a waste of time.
Bite the bullet, get the surgery. You will not regret doing it.