Hi, I understand your frustration, grapple with the same issue daily.
The fact that Pec stretches aren't working for you, would imply (to me), that your issue is really scalene related/and or cervical. Please try taking a tennis ball and (gently at first) massaging your scalenes. Does that make things better? If so, it might be worth continuing.
I can do pec stretches provided my neck isn't flared up. If my neck is flared up, then chances are, your pec stretching will backfire.
Another tip I recently learnt. Being more and more bound to the bed etc, I was propping my head up and reading. It made things much worse. If you must do this, make sure the pillow and support are from the shoulders and not the neck. Otherwise, it forces the bottom of the neck into further flexion, and activates the scalenes.
The things we learn..