You're far from alone. There was an interesting thread on r/psychonauts recently about atheist psychonauts[1], and a lot of people identified as such.
Psychedelics clearly don't inevitably lead people to become believers... but still a lot of people do, especially when they have overwhelmingly powerful mystical experiences (which we know are pretty likely to happen on psychedelics).
The most lasting message I got from my trips was "wow, we don't know shit. It sure is weird that we're all on this planet and don't really have any idea what's actually going on." No real insight into the nature of reality, except that it's pretty weird.
Well, Socrates' knowing that he knew nothing was counted a real insight! Uh, and his singular wisdom was proclaimed by a psychedelic-inhaling priestess in a temple, no less.
It didn't work for me though—in epistemology class once I said to the lecturer "I don't know anything!"—not being flippant, at the time I really felt I couldn't be 100% certain of anything—and he said instantly, unimpressed, "Don't you know your name?".. (Which didn't seem quite fair. He didn't "respond to the strongest plausible interpretation". Or maybe he did.)
Psychedelics clearly don't inevitably lead people to become believers... but still a lot of people do, especially when they have overwhelmingly powerful mystical experiences (which we know are pretty likely to happen on psychedelics).
[1] - https://old.reddit.com/r/Psychonaut/comments/oa6782/atheist_...