How frustrating all that can be. So sorry you are upset.
Sometimes insurance companies change policies to state that prior authorization is needed for certain kinds of coverage. It's possible that is the issue here and you were not made aware of it.
I would definitely call the insurance company and find out why all of a sudden the coverage is not there. Sometimes they only cover so many visits per year. In that case, you may be able to get around it by submitting a letter from your doctor about how medically necessary your pdoc is. I might be grasping at straws here, but those are possible scenarios.
I wish you luck with all this......don't forget to breathe
Hugssss
sabby