@David1280
Unfortunately AirBnB was acting in your best interests - there was something about the guest, their previous credit history or something they were aware of and so they cancelled. You then took it on yourself to accept the guest and now you have to put up with the consequences of damage and no payment. Out of interests, aside from the damage, why did you allow the guest in the property without paying you when AirBnB had told you they cancelled the reservation as that would mean zero payment (and zero security deposit).
Don't forget that AirBnB can have reasons other than bad credit for advising cancellation of a booking - bad or even dangerous behaviour by a guest in another property.
Unfortunately you are stuck with this one unless you can contact the guest and get them to pay you.