What did the therapist suggest you do to correct the issue?
What exactly is your current weekly training plan - days, exercises, sets, and reps?
The more info we have, the better advice you can get.
This isn't exactly a chest stretch.
What do you mean "overbalance the other way"?
Again, if you can layout exactly what you do each week (or at least, exactly what you did for training last week), we can get a better idea of where things can be improved.
I will say that as soon as I began starting one or two training workouts each week with a few sets of face pulls using a static hold, my back, chest, and shoulders felt (and, I think, looked) better.