So sorry to hear of your pain, katek, hope you will feel better soon.
I am in the same position, going to the physio for a torn supraspinatus (in shoulder). Most of the time she is very gentle but yesterday she really hurt me and has set me back in my range of movement, which was very limited. Nor did it help that a canvas stool ripped and threw me onto the floor, landing on my shoulder. I was doing my physio home exercises at the time!
I have had frozen shoulders in the past which have taken a couple of years to mend, but this injury is hopefully 3 months.
I would be interested in others' opinions of the following. Physio thinks I should take painkillers all the time so that I can push myself further on the stretches. When at rest I am no longer in pain, thank goodness. Is it wise to take so many painkillers? I feel reluctant.