Hi there, your situation sucks and I'm sorry to read it. If you develop a relationship with a trans woman, while staying married, this will eventually break two hearts. There is a nice short movie about this here http://transattracted.com/t/house-for-sale-2012-short-film/29/2 (though the story is a bit different, the guy in the movie is a jerk).
This is so wrong if you develop a relationship with a trans woman while staying married. First for your wife. And most importantly for the trans woman. She deserves so much better than being in the situation of the extramarital lover. You wouldn't like to hurt a woman like this. Suicide rate for transgender people is already high, there is no reason to contribute to increasing it.
But maybe this is just a "phase" for you, after all. So far if you only have sex with escorts, that is fine. Maybe after a few months, your attraction will lessen, and you will forget about it, and your family is saved. I think you need more time to really be sure that this is the attraction you want to pursue, because once you're divorced, there is no turning back.