@Jenny1066
in theory, your host should cancel but... if he is leaving the country and close all his accounts then Airbnb will not be able to charge him penalties. It is 50$ per canceled booking and if he has many future bookings to cancel then it could be pricy.
More you wait - the higher the price you will pay for your next accommodation. If you book another property before you cancel this one you will not be eligible for any refund.
The money you paid is still on Airbnb account and Airbnb is the one who will refund you. So yes, you should contact Airbnb and ask them to cancel your stay and give you a full refund including their service fee