Hello Marcella,
I just wanted to say I am a fellow NYC Co-host and our bookings have slowed down too.
We are in Queens near JFK.
We are normally fully booked 3 - 4 weeks in advance since starting in March 2017.
But now we have a few dates available in November, which is unusual for us.
I think that there are a couple of factors. For us, there are more hosts in the area. And I also found this:
According to the NYCEDC hotel occupancy rates drop in November, go back up in December, then fall off a cliff for January and February. They start coming back up in Mid March to normal levels.
https://www.nycedc.com/economic-data/travel-and-tourism
Let me know your thoughts.