I have been married for over 20 years. One of the reasons is that we don't keep secrets. We are entitled to our sordid pasts, and what happened before, happened before. Our pasts, the good, the bad and the ugly are what made us who we are today.
The thing is that eventually when a thing like "I have a Y chromosome, and that's why I can't have your child." comes out (and it will), it won't end well. Women get beaten, maimed or killed for this all the time. If you're lucky, it just gets used against you when your marriage gets annulled.
Being trans is nothing to be ashamed of. Be proud of what you've accomplished and overcome. Having a partner to share that with is truly priceless. Who wants to spend their life hiding from someone who could turn out to be a transphobic bigot anyway?