...wow... I'd be over the moon if something like that were to ever happen to me! Just... wow!
I'm in a bit of a bind atm, where the stubble from leaving hairs for my electrologist to zap appear too long to make the lady's room much of an option. However, I'm out at work, and all my IDs show the new name and gender marker, so going into a men's room would be awkward socially, as well as personally. In short, I only use the women's room now, but there are certain circumstances where I'm outside, and still have to just hold it.
The breaking moment was when I was at a movie with my girlfriend. She went to the restroom before the movie started, but there was a line so I tried to hold it. Couldn't. Couldn't focus on the movie, couldn't think. HAD to go.
So I left the movie in the middle, which I never do. I walked outside, and turned to the lady's room. My girlfriend wasn't with me... I saw some girls go in, and saw it full of people inside. I turned to go back in to the movie, and realized I was going to have an accident if I didn't go. So I prepared for embarrassment and started toward the men's room. I got a few steps toward it, saw the sign, saw the men going in, and just... couldn't make myself do it.
I turned around, took a deep breath, and went into the women's room. The fates for a rare change smiled on me, and the first stall was open. I went in, sat, shaking, and did my business. Then I got up, washed my hands, head down, and left. When I got back to my seat my heart was pounding, kind of like a panic attack but more exultant.
And overall, that was it. There are still moments where I won't go, or will wait, or feel various levels of anxiety for various reasons. But that was the last time I seriously thought of sharing a bathroom with men. It kind of broke the worst of the fear.