Is my constant, internal self-evaluation rare, or does it just seem that way?

Yes, but try to find joy in life instead.

You seem very rational, responsible and a perfectionist

So why aren't you out there volunteering to help others and get the focus off of YOU!~?

I do think it is more about those that are more vocal then others that do feel as you do. More often than not, quiet and properly blaming people or self is just what is looked for, but not always found as business would want it to be. As a matter of fact, the real way to get raises and promotions is to always look good, and never let it be known about any frack ups.

So no, you are not alone. I always think in patterns I trained myself to think, where it is the immediate, the not so immediate and the historical. Doing that often helps me to know just how much I myself flocked up.

Maybe not, but the other people around you probably have their own obsessions, like you, and some might even come under the same category. Don't over analyze. That will lead to further isolation, and self-loathing. Analyzing feeds on itself.