I thought I would do better somehow than I have done
This perplexes me. You have so very much of what I deem success. You have tenacity, too! You made incredible adjustments after your stroke, so much so that I can't tell from your writings. You seem to me to be antifragile to the maximum. Did you expect to have more money? Too many of us gauge success by money, another topic altogether.
I could never have guessed the trajectory of my life while I was a child, teen, or college student. I thought I would get an advanced degree and go into academia, if I thought anything at all. While I do hold an advanced degree in mathematics, as soon as I got out of the education quagmire, I went into feeding people, and that was that. I did well, not extraordinarily well, but well enough to have retired (unexpectedly) at age 55.
I learned how to be open to other opportunities, one of my greatest strengths I believe. When disrupted, and I have experienced some very traumatic disruptions, instead of getting depressed that my near future was not what I had planned, I looked around for unconventional ways to navigate. I did things most people would not have done. I was willing to let my plans go, to see where that would take me. It worked very well.
I love someone who recently made a "bad" choice for his intended career. He got severely depressed about this. I suggested that perhaps his career was not really what would make him happiest, would make him feel successful. He is now happily considering a range of other occupations. All he needed to do was to let go of his lifelong plans. So was that "bad" choice really bad?
But is it too late to make a significant change and pivot toward something meaningful?
Never.
I think I expected to have less struggle. Times of ease and joy, rather than just constant grind to survive. It isn't that I have done badly, just not as I had hoped. I wish I could provide more for my family than I do, across many areas.
Was there a clear guiding force, or did it just happen?
It is the "letting go" that we mostly struggle with, right? This is what holds the status quo in place, because people don't want to lose what little they have, even if it means having more of something else more valuable.
One guiding force for many is that once you have had a job in a restaurant, it is easy to find employment everywhere you go. An incredible opportunity landed in my lap while I was looking for a job in computers programming. All I had to do was say "yes" when a the only restaurant I applied at called me in to wash dishes one night. And the rest is my history, up until age 55. My father may have asked me when I was going to get a real job until then, too. I didn't live up to his expectations. Maybe a lot of these traps are because we are trying to live up to someone else's expectations.
AND what causes the status quo option range to become narrower and narrower, until we are essentially slaves.