The only alternative to surgery is to get it moving. It's painful, but so is surgery! And after my surgery I had to do 6 weeks of physical therapy--getting it moving--anyway. When we feel the pain, we tend to cradle the arm to ourselves, which just makes it more immobile.
When my other shoulder showed signs of the same, I began the exercises--standing facing a wall walking your fingers up the wall works well. The therapist also gave me a sort of pully with a rope and two handles to hang in a doorway. Then you sit in a chair and sort of "see-saw" your arms up and down, lifting one at a time and pulling down with the other hand. Works great!
Will be praying for you!