This sounds like me too. Completely restructuring meaning after losing most of my outoodr physical pursuits. Still being able to do a few things but at a radically different tolerance level. It's tough to readjust to that. If you feel like hiking a mile uphill is like what climbing a mountain used to be like...and then pay for it with a lot of pain sometimes for days after...well that's just tough. Still, we are lucky to be alive and to be able to do what we get to do. I can't really put a more positive spin on it than that.