And while I would answer 'no' to that question, the amount of evidence that there is something supernatural* if far greater than the amount of evidence that there are millions of people lying about their experiences.

Surprisingly, no. That said, religious people aren't lying. They're not even a lot crazier than baseline. I've had experiences which I recognize from my reading to be neurological that I might otherwise attribute to some kind of religious intervention. And those are coming from an atheist's brain not primed to see angels or gods or anything of that kind.

As for why belief in the supernatural is everywhere, a lot of it has to do with how bad our brains are at finding satisfactory explanations, and at doing rudimentary probability theory. We existed as a species for a hundred thousand years before we got around to figuring out why there was thunder. Before then, the explanation that sounded the simplest was 'there's a big ape in the sky who does it.' And, even when we knew the real reason, we were so invested in those explanations that they didn't go away. Add in a whole bunch of glitches native to the human brain, and boom, you've a thousand generations of spooky campfire stories.

As was suggested, misremembering, and group hallucination are possible, but if that is the case than I should probably check myself and some people I know into a medical clinic because I would be forced to consider myself insane.

If I were you, I would be terrified of that possibility. I would at least go to a psychiatrist and try to rule it out. It is a real possibility, and potentially the most likely one. Just because you don't like it doesn't mean it isn't true.