Scott, a similar thing happened to me earlier this year. I'm building a house for the wife and some of the things I need to do are up there a ways. I was on the second level and getting ready to put some soffit material in place when it hit me. I was holding on with all three hands. How could I get anything done? I fought it for a while. I tied off the ladder. I did something else. I took a break. It took me all day to nail up one piece of fascia. What's up with that?
Long story short, I had plenty of other things to do, and several weeks, or months later I went back up the ladder. No problem. Got 'er done.
I don't know man. Sometimes the demons just seem to be there.
You know the joke about falling; it's the sudden stop that gets you. I tell folks all the time I'm not afraid of heights, but I'm danged respectful of falling. I'm similar age and size as you. A few years ago I was driving over a bridge and wham! I was scared to death. I'd never had a problem with bridges before. Now to be sure this old bridge was on it's last leg, but I'd driven it hundreds of times before. So yes, to answer your question, there's others out there with acquired phobias. After all, we aren't born with them. It comes from our environment. I look at it as a maturing phenomenon. When I was young, I didn't now enough to be afraid. Now that I'm experienced I know a few who tempted fate and lost. Those ladders and bridges were just a means to an end when I was young, but they don't look quite so safe through the dim old eyes of a gray haired man. Pick you battles. And tie off your ladders.