I was down a full year with this one. Dont irritate it or it will continue to have you down months. Yea doctors mri everything. Rough boat to be in. Total time off training one year. Followed by bpc and tb and starting back with very very light dumbbells for chest. Took a year after taking a year off to get back to 70s 80s for chest. Good luck.

Ive just had to modify what I do. I do light weight, high rep lateral raises but mainly focus on overhead press, upright rows, and any other shoulder exercise that doesn't cause (as much) pain. My reverse flys have to go high / mid. I also have to heavily focus on dropping my shoulders on machine flys and bring my elbow a little more in than I would traditionally like on my bench press. I also use a Swiss bar at least one day a week on bench rather than a traditional bar, to rotate my elbows and shoulders more in. I also make sure I do stretch and warm up to get the blood flowing before adding weight. I do shoulder rotations for 60 seconds and regular stretching, then warm up with incline bench at ~40% weight. Anything to get the blood flowing...

Not sure about impingement specifically but I ran 2mg of BPC/TB mix for 30 days combined with not doing any exercises where I felt the sharp. pain. band stretching, and tendon strengthening exercises(just look up on youtube) and my shoulder went from 60% to know feels about 95%. I stretch and do those exercises everyday i'm at the gym for warmup except on leg days.

I had the doctor told me to lift with it and it would tear and I could get surgery.
Then I took the advice from a powerlifter at my gym that is a physical therapist at an old folks home. He told me to completely stop lifting with it til the pain stops. Then to work out with rubber bands and showed me exercises to strengthen my tendons. I did just that and I didn’t need surgery. I’m fully recovered. I couldn’t even open a car door for a while because it hurt so bad. Hope this helps. When it hurts to lift your body is telling you something. It sucks to not work out but it’s better to wait a month than to have to never lift for years because you tore something

Might not be too late for PT (physical therapy) but it will take 2-6 months of diligence on your part to fix if it even is fixable with PT. If not, tb and bpc may help. Or surgery.

Have you seen a DPT yet?

I have a fucked up shoulder. I just try to work around it. Short of surgery not much you can do. Obviously stretches and avoiding incline barbell presses and certain bicep moves. Kinda comes and goes. When it's feeling good I go hard and adjust when the pain is bad.

Not sure if any of that helped. Getting old sucks