Internal Impingement of Shoulder?

I was in a full arm cast for about 2 months a few years back, and ever since then my shoulders a little off. When I golf or swim, the next day I get pain in the back of my right shoulder, right where the rear delt/infrasupra muscle sits. The pain only shows itself when I internally rotate my arm, and it goes away after a couple of days.

Also, overhead movements like overhead pressing or pronated pull ups cause discomfort in this same spot. Feels like my shoulder won’t glide properly, almost like it wants to pop.

Lastly, if I sit in a chair for long periods of time my shoulder begins to ache in this spot.

All of this makes me believe the muscle/tendon back there is being impinged with overhead work or internal rotation. Reading online, I think it may be internal impingement but I’m not really meeting all the symptoms.

If it is internal impingement, does anyone know how to begin resolving it? Or does anyone have suggestions as to what it may be? I’ve been doing scap protractions and some lower trap work, but it hasn’t shown any improvement.