I think your email answers your question. No one says they are divorced by accident. If his ex-wife is married, then that leaves a heck of a lot of explaining. You haven’t done anything to cause his concern about money, and he completely disregarded the agreement you had about not buying the gun. This leaves you with a man that lied about being divorced, lied about the agreement to get the gun even though he knew it was a deal-breaker with you, and tells you that YOU are not trustworthy.
I’d highly recommend all of these issues be dealt with prior to making your commitment.