Praying for you, Keith.
I am not far behind you. Since my knee replacement 14 months ago, my gait has been off just enough to throw my direction off a few inches here, there, and yonder, and stepping on a slightly higher rock or bump or just a low spot almost makes me fall. I am well aware of it and my wife has noticed it too. My legs are the same length, so it is not that. I exercise on an exercise bike, so I am not immobile. And I work part time 4 days a week most weeks.
The problem is I have arrived at the situation almost to where you are, and I know that I am a step away from a fall. The certainty of total stability while walking or even standing without something to lean is just gone. My doctors know it and tell me to "be careful". "Use a cane, take one with you even when you don't think you need it."
I did not expect to get this way this quick. My mind is fine (OK, No comments from those that know me

) but my body is playing tricks on me too. Praying for you!