I had a frozen (right) shoulder about 5 years ago, aged 44. It was agony - I've quite a high pain threshold but this really knocked me for 6. GP referred me to hospital (took 6 months for appt) whereby I had a variety of scans & xrays to check bones/skeleton were not damaged.
Initially (pre frozen shoulder diagnosis) I saw a physio to begin with. I then stopped physio after a few sessions as it was then officially frozen shoulder & was advised to not have any form of surgery, it might cause problem later.
Could only sleep on my left side for 6 months & positioned pillows to stop me rolling over to my right in the night. I then always felt I had a sore left hip due to the constant sleeping on the one side.
I did the mobility exercises with the band to push my arm/shoulder into moving again, it was agony!
But I tried to have a positive out of it - it forced my left arm into action (I was v one sided) and I became better with eg emptying washing machine with my left arm & it's strength definitely improved thankfully.
All together, it took 2-3 years to right itself and I've 95% of the movement back. Were I to do the backstroke swimming, it would be obvious to a trained eye the difference in each arms' circulation movement.
At the gym now, I do extra stretches on my right shoulder just to keep it moving beyond the normal range of movement.
Finally, I've a desk based job so got a keyboard and mouse support thing where I can rest my wrist which helped.
Wishing you as speedy a recovery as possible but set yourself up for the long run I'm afraid. HTH