I'm going to go out in a limb here Teresa. You know where you are on the spectrum. I also believe you know what you have to do. The issue is you are looking for validation and maybe permission to do what is necessary to relieve your pain. I know how difficult that is with a spouse that accepted dressing and expression. I can't imagine what it's like with one that wants nothing to do with it.
Stop pushing to include your wife in therapy sessions with you. The last thing she wants to hear from your therapist is that you need to express more or even mention transition.
Transition!! Wow scary word. Yes it should sound scary because it's hard work. Many things in life will change. Some for the worst, some for the best. You are fearful for your marriage. But that could implode for many reasons you have stated without transition.
GD is very similar to fluids. It will eventually find it's own level. Things can be good until they are not. In your case they are not and you have yet to find your level. Unfortunately the only way to mitigate your pain is too explore. Your thoughts identity,, feelings, expression and interaction with the world. And as harsh as this sounds. If you need public interaction and expression, then either your wife is supportive or tolerant or it will end. Unless of course you need to transition. From your posts I would say it will end. You will need to ask yourself, and only you. What is my identity. How will I want to interact with people in five years. As male or female. Tough stuff. You have to do the hard work and heavy lifting to find relief. Nobody can do that for you. Your therapist can suggest things. But it's not her job to declare you are CD, or gender fluid, or TS. Only you can know that. She can offer ways to explore your identity. Ideas that you can try to see how comfortable you are. Try facial hair removal. See how that makes you feel? One of two sessions will not have any long lasting effects.
You are infatuated with your therapist as she has given you validation. Guess what. That is her job. Pursue a relationship with her and I guarantee you will poison the professional relationship with her and hasten the demise of your marriage.
Only you can find the relief and inner peace you need. And it's very possible that you will need to travel that road by yourself without your spouse. Take comfort that your children will probably be able to walk that path with you. Or at the very least support you emotionally on your way.