At this point you have 4 choices.
1). Be faithful to her for the rest of your life and forget about your infatuation with trans women. = fair and loving.
2). Divorce her = break her heart.
3). Tell her about it then divorce her = break her heart then rip it out and stomp on it right in front of her.
4.) Cheat on her = possibly catch something and give it to her, break her heart, then rip it out and stomp on it right in front of her and have her take you to divorce court and make a total fool out of you and pay out the ass for God knows how many years.
obviously option 1 sounds like the most fair and reasonalble option. But let's face it. That ain't never gonna happen. Options 3&4 would be totally cold hearted and chicken shit to say the least. So it looks like option 2 is the only viable solution here.