Ok, so here's a thing. My critical thinking skills got me to the point where the nuts and bolts of Christianity didn't work for me. But I still experienced God as real, just something that I had to lose my dogmatic ideas about. Then, one day, the feeling of realness stopped, like a light switch being flipped. It was there one minute, then it wasn't, and it scared me witless at the time.
Looking back on it, the only way it makes sense is to think that my brain was firing on a 'god is real' wiring, and something made that stop; it literally was like a switch going off in my brain. No idea what made that happen (I wasn't in a crisis of any kind, there was no physical injury or illness or a big life change), or why it was so sudden, but it is the only thing that makes sense.