Shell, I floated along for twenty years until my world fell apart as quickly as it took to wait in a post office queue. When I had finished I could hardly move. I was so gone mentally that I thought the sensible thing was to phone up my husband and ask him to bring down my bike so that I could cycle back home.
One thing, though, I have never been in pain, thank goodness. So do take a break from NAC. Its only essential in the later stages, when you are thinking of stopping full-time abx, to help guard against re-infection.
You doc said you looked a lot better, I said you were sounding better, your utis have stopped, so you're on your way!