a few thoughts:
What is your form lke when benching? that is the # 1 culprit.
try cutting out heavy bb benching and OPs, go with close grips and lots of dumbell benching for reps
rotator work? are you doing it? cuz that is what a PT will prescribe after a costly consultation
lots of rows, upper back works (pullaparts, bent laterals, face pulls, shrugs, pulldowns to all angles)
I combat bad shoulders on a daily basis, lol, my current max bench shirt is in the 700s.....