Although “faith crisis” has become a bit of a buzzword, there’s a real phenomenon beneath the fad: sometimes your expectations and assumptions collide catastrophically with new information.
You have three options when this happens. You can try to pretend nothing has changed, but if the new information is real, this denial won’t last. At best, it’s a delaying tactic. Eventually you will have to either walk away from your former beliefs or rebuild them.
One great example of a faith crisis is Paul. Prior to meeting Jesus, he thought he had it all figured out. Meeting Jesus demolished his old beliefs. He knew he was wrong. But he didn’t know what to believe instead. Not on an intellectual level, at least. According to N. T. Wright’s biography, Paul spent years figuring out how to take the raw material of his old beliefs (especially the Hebrew Bible) and put the pieces back together so they fit his knowledge of the Savior. (This is the third option.)
Nephi is another example of a faith crisis, but the depiction in the text is a lot more subtle. Still, the pieces are there. Start with 1 Ne 2:16: