You should have been looking elsewhere. We have a similar situation in Washington with our Blue Cross provider, who is on the exchange, but our Blue Shield provider is not on the exchange and has a much more complete network.
The only compelling reason to use the exchanges is if you qualify for subsidies.
Do you have any recommendations of good places to look?
I tried to look up plans on my former insurer, but they just referred me to eHealthInsurance; after entering my zip code, eHealthInsurance came up with a handful of plans from a single insurer that were all on the exchange.
It's entirely possible you're just screwed in whatever county you're in, but I don't know how exhaustive eHealthInsurance really is. I didn't use it, though it does show my new off-exchange plan. I already knew which company I needed to go to since I wanted a Blue Cross or Blue Shield plan.
What I would do is assemble a list of every health insurance provider in New York and directly visit each website and/or call each company to see what the options are in your area.
I'd also check with an actual insurance agent who might have a clearer picture of the situation where you are. Even though I knew I needed to go to Regence Blue Shield and that they have coverage in my county, I still went to a local agent to help me make sure I got everything right.
EDIT: NYT actually did an article on this in October[1]. They point to eHealthInsurance, but also GoHealth.com, which I haven't seen before.