supraspinatus + Teres minor at gym

Hi everyone,

I have a nagging condition and I wonder if you could guide me a little please.

8 months ago, hurt my shoulder at the gym (most likely a Supraspinatus tendonitis according to the physio). Had to stop and took physio sessions for a little over a month, following that the pain subsided quite a lot. Had a discomfort while taking off the t-shirt (elbows perpendicular to floor and pushing in to torso), which also disappeared after 3 months or so. Just resumed weights again after 7 months and the pain in the same shoulder has returned although at much lesser severity.

Examination is:-
1) Infraspinatus test https://www.youtube.com/watch?v=g8xtOqZFTwo at 5:35 is negative, however, if instead of keeping the elbow to the torso, if I take the elbow out by 30-40 degrees and then do the same test, then there is a pain.

2) Next I did the Teres Minor test, (https://www.youtube.com/watch?v=WOabOI2Z4FA). It's, certainly, positive. This time because I am also pulling the hand in while pushing the elbow out, the pain is significantly more this time. The pain seem to increase with the angle away from the torso.

3) The full can test at 5:50 is negative but the empty can is, clearly, very painful. While performing the test, I feel no pain as soon as I release the pressure, there is a sharp, significant pain.

4) Last test is at 1:20 of this video https://www.youtube.com/watch?v=GIureJZfHUQ
If I do this stretch in which the elbows are at the bench and I am trying to bring the hands towards my head and away, then I feel quite a sharp pain which starts when the hands are at 25-30 degrees and increases as I bring the hands towards my head. The max pain is when the hands are perpendicular to the floor. However, interestingly, if while doing this stretch, if I hold the position of pain for 20-30 seconds, the sharp pain disappears completely. During the movement, starting with the arms parallel to the floor to then being perpendicular, I stop and hold a couple of times for some seconds and the pain stops fully. However, after 30-40 minutes of rest, if I did the same stretch again, the pain would come back to the same level and I then hold the positions in pain and then the pain disappears.

I have taken the physio sessions, which helped a little but obviously hasn't worked fully and had to stop gym again because of the condition.

Could you please tell me a diagnosis of my condition, given the above information?
Could you please suggest a protocol to recover from this condition and also how to avoid it in the future at the gym. Lastly, why is it that holding the position in which I feel pain for 20-30 seconds, the pain disappears fully.

FYI, doing barbell shoulder pull ups, I started to feel this pain 2 weeks ago. So, had to stop. Appreciate your help, cheers