@Kassy6
No. It's really bad form to ask a guest for more $ after the fact. It's unfair and will make them understandably angry. It's a host's responsibility to keep their calendar and pricing up-to-date, your future availabilty should all have correct prices on the dates.
And if the guest reports a bait and switch like this (although I realize that wasn't your intention) to Airbnb, they could suspend your listing.
You're going to have to eat this one and chalk it up to a learning experience. Many hosts, especially newer ones, get caught out on this kind of thing.