Hi, @Pat347 . Things like this happen, and, I agree, it's hard to take, especially when you are new.
I do have some advice about the response. It's public. Take a look. You have put your lockbox code out there for all to see, and that will be an excellent reason to ask Airbnb to take it down.
You will absolutely want Airbnb to take it down for another reason: because the review says only nice things, but you have written a bitter response, which gets posted to your own page and reflects badly on you, not on the guest.
I would call Airbnb right away if I were you.
All the best. As you know, most guests are lovely, reasonable people. Hope you get lots more!