Hi there,
Im not a physio or doctor, but i had something similar happen to me last year when i slept on my side, with my arm extended above my head and slightly twisted. I couldnt lift my arm to the side, above my head, or in front. Turning the arm or wrist, like when twisting a door handle, was extremely difficult. I finally had an ultrasound a few months ago and have been diagnosed with a partial tendon tear in the Wikipedia reference-linkrotator cuff affecting the bicep long head. Ive also got inflammation in the entire sholder area.

I started physio about a month ago, twice a week. Its been slow and have gone back a few steps already for no apparent reason. Ive also been told Im losing stability in the anterior shoulder and its affecting my neck as well. Im doing pilates and light strengthening exercises with the band to try and coax it along.

I would try and get that seen to asap as it could be worse than a partial tear and either way, you'll need some help to get it mobile again and heal the area.

Good luck.