@Ellen82 & @Cathy545 , I'm sorry to hear this situation is affecting you negatively. All my bookings for the year are out the window too.
I've always approached AirBnB, and any booking platform for that matter, with the following mindset:
AirBnB = on line retailer
Guests = customer
Hosts = product
AirBnB, like most on line retailers, is going to refund the customer 100% when they are not satisfied with the product, even if it has nothing to do with you as a Host.
The only thing you can do as a Host is protect your "product's" value. For me that means choosing a Strict cancellation policy (despite AirBnB constantly prompting me to switch to Flexible because it attracts more guests), setting my pricing 10-15% above AirBnB's recommended minimum, using smart pricing, make my property available through other channels, make my property convertible to other uses like LTR, and put away 10% of my revenue in a contingency fund.
I know it won't do much for your existing and cancelled bookings, but hopefully these tips, many of which I picked up from other Hosts in the community, will be useful to you going forward. All the best on that front!