@Maureen10 Can't say if Airbnb will waive your cancellation policies or not, but you need to get on your calendar right away to avoid guests requesting reservations beyond your 3 week maximum availability. I looked at your calendar and as it stands right now, I could ask for a reservation in December!
Here's what you need to do:
Go to Manage Listing > Calendar. To the right of the calendar in the upper right you will see Availability Settings. You can choose "I want guests to arrive within ..." You have a choice between 3, 6 and 12 months. Select 3 months and then manually block dates backwards to your 3 week limit. You'll have to manually open up dates on your calendar as time goes by.
As an example, I only want guests to arrive within 4 months which isn't one of the options. So I selected 6 months and then blocked the two previous months. I have to monitor my calendar to open dates within 4 months.
Do this right away and if you have Instant Book (I didn't check) turn it off until you get your calendar sorted out.
Does this help? If not, get back to me!