You've received so much feedback, so I imagine my comment will be lost in the weeds, but I'll say it anyway.

I want to work with programmers like you. I really do. I don't want colleagues that can dive through stacks untangling complicated messes effortlessly. I want colleagues that are sensitive to every cognitively burdensome aspect of the codebase and _need_ to fix it to continue working. These are programmers that will be methodical and wholesome in their approach, and will deliver code that is easy to work with. I'll choose a programmer like you over a young-gun-star-code-cowboy every day of the week.

That said, if I were you I'd ask myself if the problems I'm having are inherent in the problem I'm solving, or in the approach I'm taking. I'm somewhat younger than you, but I have horrible working memory (sounds similar to what you're describing), and my self-development as a programmer has been mostly centered around finding ways to make that irrelevant.

Also, you might be interested in the Huberman Lab podcast. He's a neuroscientist and has episodes about ways to improve things focus and creativity.