Hi Anna, you and those who have responded make a lot of good points.
I have a genuine question for you. Do you regret telling her? For me, what really triggered my need to come clean with my wife was the thought of living a lie for the rest of my life. Before my big reveal, I would have accepted the situation you are in as better then continuing to live the lie. Do you feel the same? Is DADT better then hiding?
Another thing. While your wife may feel that if she had known sooner, she may not have stayed with you, I bet she doesn't regret it, particularly as she wouldn't have had the children she does now. Hers and your children wouldn't exist without you! I don't think many women (probably none) would give up their children for another set of hypothetical children that didn't have a father who crossed-dressed.