@domcib: I have been through this too. What helped me the most is to get good at skin the cat (best pec minor stretch their is in my opinion), look up some Kelly Starrett joint distractions, especially the snatch prep and the front rack position.
I’m not into isolation work, but I used a shoulder horn 3 sets of 25 every six hours for as long as you can progress increasing the weight as long as there is no pain (make sure you eat well, I tripled the weight I used in 3 days doing this, I can’t stand not being able to train lol) then every other day after my workout I rotated 3 sets of 25 with 1 set of 5-8 minutes straight only increasing weight after you can do 8 minutes straight.
I also would lay on a foam roller with dbs - think upper arms straight out and just let them stretch you into internal rotation like you want to tap the floor. I had success with the Kelly Starrett best IR stretch (it’s a barbell smash). Now I didn’t experience pain with this stuff and wouldn’t have done it if I had, and I’m sure you’re the same, but I feel better typing it out. : )
Before this I had went to an ART guy and he told me I had scapula winging and I shouldn’t do anything but a bunch of scapula retraction exercises for 3-6 months. I couldn’t stand the thought of taking that long off so I figured out a quicker way.
I started doing a lot of shoulder dislocations 1st with a band, then a rope or pvc after every set of bench as well. I became almost OCD with my form too.
All this started with me when I was at a computer for obscene hours a day because I quit my job to start my own business. So I became very aware of my posture because I figured if I didn’t I wouldn’t be able to workout and that wasn’t an option for me.
I hope you find this helpful and are able to do this stuff pain free so you can get back to being you in the weight room again.