Ok, don’t panic this is fixable. How about if you call the insurance company again and tell them what you just told me. They can go back and check your previous authorization and use that instead, cancelling the new request.
Honestly, don’t be so hard on yourself. You didn’t screw anything up. You are under a lot of pressure, stress and are facing the clock on treatment. So it’s understandable you’re feeling panicky. I think this little glitch will be a matter of trying to remain calm and explain this to your insurance liaison person. This will work out.
Or, with the visit to your new doctor, maybe they’ll be able to get your prescription pushed through. Did you have that appointment this morning?