Welcome back, Ernie. I wandered away and found my way back about the same time you did. I'm sorry to hear about your back. The loss of confidence I think is natural when you're out of practice. Knifemaking is a feel thing as much as a logic thing so when the hands aren't engaged, and the mind tries to make sense of it on it's own, it's like trying to grab a handful of sunshine...it's there, but hard to get hold of.
What you have learned won't go away, when the time comes to pick it up again the hands will remember and the mind will clear.