I can relate to that. I finally swallowed my pride, and started using a cane. Bought me a fancy one, not a plain old-fashioned candy-cane type. Using it has made a difference!
If he retires the office, what do they call him? ExPope, Former Pope.
Benedict is now referred to as "Pope Emeritus". So I'm guessing Francis would be "Pope Emeritus" also.
Maybe we can start numbering Emerituses:
Benedict: Pope Emeritus I
Francis : Pope Emeritus II