Welcome to SR! Please go to the Dr. appointment, be honest about your addiction. He/She might tell you things that you disagree with, but be open and be prepared to change.
I know, you know, how important your children are. Please talk with your doctor, create a plan to quit oxy and execute that plan. I know you have it within you to do this, and I think you have the drive and determination to do so.
Good day friend, be well, I am rooting for you.