You're definitely not crazy.
How can you know if you can possibly forgive and reconcile, if you are not sure if you know (fully) what you're dealing with. You know one thing for sure, the person who is telling you what happened has betrayed you and lied to you. I'd be digging for more information, too.
I can't shed any light on the reconciliation process, since I haven't experienced it. It's easy to see it is a difficult road under the best of circumstances. A marriage is built on promises (vows), commitment and trust. When those things are blown apart, they can never be put back together, but instead have to be rebuilt with something new. The starting point is a remorseful spouse. I never had that, so it was clear to me that reconciliation would not be our outcome. It seems that your H is remorseful, so hope exits. Good luck to you.