I second "stretch" therapy. Froze each shoulder, one 20 years ago, and the other recently. Both times used little overhead pulley with clothesline rope to do stretches (thanks, mom!). Knotted rope on each end. Grabbed knot with each hand and used good arm to pull the other up until it would go no further. Made marks on rope to measure progress. Did several times a day. From not being able to raise arm high enough to get hand in pocket, went all the way to full recovery--total overhead stretch with no pain. Took a year first time, but when 20 years older, took 1-1/2 years :-) Still, no surgery.... So it takes a while, hurts a bit (hurts a bunch when you first injure it), but gets better and better over time. Just keep at the stretching.