Hi bshark In my experience although there often feels to be a tipping point where symptoms either change or become alot worse, it is a continuum. I see it as a hillside sloping away out of view, the further I slip down the slope the steeper it becomes and the harder the climb back. The more aware I can be, the sooner I can back off and the less ground I lose.
My worst times are when this almost intuitive awareness is over-ridden by 'stuff' like doctors and hospitals. I know it is coming, I try to prepare and it always leaves me floundering and struggling to keep my life on track.
Give yourself as much slack as you can and let the doctor know of your particular vulnerabilities, they can sometimes be really good. I no longer participate in medical activities that will damage me and I make that clear to the doctors, usually they respond well.
I can only wish you well, things are changing and lets face it they can't get worse.