I'm a fine one to give advice on this matter, but I'll do it anyway. It's easy to ignore it if it sounds wrong.
Everyone has to make a decision at some point whether or not to be honest with your spouse about your sexuality. That holds even if you do nothing, i.e., default to keeping it secret from her.
Of course, if coming out about your gender identity is likely to ruin your marriage, it's best to err on the side of caution. You should ask yourself, what's the upside to disclosure? If it's not going to change anything, why bother?
With 20/20 hindsight, I wish I had come out to my wife 30 years ago. I had no idea how she would react, and I wasn't brave enough to find out. Of course, 30 years ago, I knew squat about gender identity disorder. I didn't know WTF was wrong with me.
When I learned what GID was all about, I had a basis on which to explain my deepest desires. That was the first and necessary step. I had to accept myself including my female identity before I could expect someone --anyone-- else to accept it.
If there's any sense that you will be accepted for who you truly are by your spouse, it would be a shame if you didn't try to share that part of you with her. On the other hand, if you doubt she would be tolerant, much less accepting, I would not risk disclosure, at least for now.
Good luck, Scott.
Clara