Snagged in the trap - all four limbs (marriage).
Sorry if that sounds harsh, but from what I'm reading marriage was seriously premature. She knew what SHE wanted - and got it. Out of your concern and love for her, you conceded. Now it's a lot trickier. She's holding the trump cards it seems because as much as you two may have flitted around the topic of poly, it was apparently all a game on her part. A game it seems she's won at this point.
I'm not wanting to paint her in a negative light really, as we only have your words and one side of the story. But the reality is, she has little incentive (at least far less) to do the work necessary to see if you two can have a successful relationship in a mono/poly configuration.
It seems all you can do is take some time for some deep soul searching and decide if you can be happy & content with just her - OR - force a confrontation ASAP. Time is your enemy now. The longer you let this linger the more difficult it's going to be to confront the truth. If you honestly believe that poly is your heart's truth, it cruel and unfair to continue to play the game, dancing around that truth.
Hard days ahead my friend. Hang in there.