I don't know the answer to any of your questions, but was just in a situation of forced medication change also. I am waiting for my fiance to pick up the correct meds on his way home.
I am sorry that you have to go through this. I too was changed to morphine controlled release and did not care for it. I used b/t meds all the time, and it began that bowel and stomach issues all over again. Just keep your appointment with your doctor, and hang in there.
Sorry there is nothing more I can do for you, or at least answer your questions. My heart goes out to you, and I hope everything gets sorted out for you quickly.
Warm, gentle hugs,