I welcome you to our "family of the sky". So sorry that you have been battling this disease for 16 years...that is a long time.
I do not take prednisone, but i have seen many conversations here about people trying to taper off, and the various difficulties. I am sure that some of the knowledgeable members here will be along very soon to help with your question.
again, welcome, members of WHL are always here for each other.