@Robert5942
I'm confused when you say the apartment isn't on any of his listings anymore. What do you mean by that? Do you mean it's no longer on his profile? Can you still access the listing from your booking, or has it disappeared from the site completely? If the latter, are you sure your listing hasn't been cancelled? What about his other listings? Have they had more bookings/reviews?
Have you tried messaging the host just to check that your booking still stands?
If you are truly concerned, I would contact Airbnb about it. It's difficult to give much advice here without more details.