Welcome to Susan's, Sarah.
50-ish, married with child/ren. There are others here, and elsewhere, who are in the same position. I do so understand your concerns and feelings an loyalty to your wife and child. Those are always difficult balances to weigh, for anyone. And I also understand the need to live one's life as herself. Like I said, hard things to balance.
The easy thing to say would be "you will be no good to them if you don't be good to you." Well, that's certainly correct in some ways, but it isn't, imo, the only and deciding aspect of whether or not to transition. I believe you stated elsewhere that you are not currently doing so.
I do agree that discovering who one's self is, or at least parts of that self we have hidden away, mostly even from ourselves is a wonderful first step, at any age. But there is si much more to "self" than simply an interior knowing or desire, right?

And you need to be able to accept that as well, that your self has all of those little bits of those you love beyond life included in the mix that makes "Sarah." Such difficult choices we come to in our lives.
I don't know, in fact I am pretty certain, that no one can just cheer-lead you into a transition. None of us outside yourself is gonna have any clue about what moves you and strengthens or weakens you. But, perhaps as we learn to talk together as a group such things will become clearer to you.
If that is what you are coming here for, then I imagine you'll find it. Susan's has many intelligent and caring people who write and read here. It's nice to add you to that number.
[on the topic of T: depending on what the dosage is it's not unusual for post-op women to require some T for health and wellness reasons. Happens a lot. Although I suspect the dosages you are gonna be prescribed would be an effective "male" boost and not simply a bit added to impact energy and as a prophylactic against bone-loss, etc. In that regard you may actually decide you should "come out" just to be able to talk about it with your wife and doctor. I don't know. I expect no one here will, except you.]
As you try to make sense of things and weigh your options, please know that you are among people who are willing to become friends, even through our limitations.
Thank you for becoming "one of us." Welcome,
Nichole