I don't know if I fit your criteria. No kids, retired, parents passed on. But damn, it sure felt like I had a lot to lose in my marriage! My wife was, in many respects, the source of my stability. I really didn't know what I would do if she left me. I was the source of the majority of financial assetts in the relationship, and I would lose half of that if she left.
Realistically, I had good reason to hope that she would stay. She was LGBT-friendly, and had enjoyed several of the early trans-themed movies: Boys Don't Cry (TW: Well-made film, but
don't watch it!), Trans America. But still, you never know. She might have decided that she only wanted to be married to a man, and I wouldn't have blamed her if she had left.
Perhaps I didn't have that much to lose in comparison to you or others, but it sure felt like I did! From the time I decided I needed to tell her until I actually did was six months. All that time was spent agonizing over the decision. So many times, I opened my mouth to speak but the words wouldn't come out. When I finally said it, it was such a relief!
What tipped me over the edge? Well, I had help from the fine people here, especially HappyMoni, who checked in with me regularly with PMs to the effect of, "Well did you do it yet?"
But the big thing was thinking about how my life would be if I didn't transition. I would live out my remaining years knowing that I was female, but consciously living a lie. Little things that already drove me crazy, like buying clothes that had to be drab and dull, would get 100 times worse. I could picture myself in a nursing home, remembering that I had had a chance to be free but I turned it down. I have never been clinically depressed, but I could tell that that was my future. All I could see ahead if I didn't transition was misery. And I couldn't face that future, I couldn't let that happen. I had already lived at least 2/3 of my life. (I was 61.) I needed to live the last 1/3 as myself.
So I knew I had to speak up and do something. My mantra became, "Gotta do it. Gotta do it." And I did it.
I knew that I was gambling my relationship. But a 50-50 chance of success was a lot better than the 100% chance of failure if I didn't do it.
The gamble paid off. My wife stayed, and I am so much happier. I get to be me!! Squeeeeee!!