If you're looking for a content management system that you can host yourself it might not be exactly what you're looking for, but you should check out Satellite, a blogging platform that I've been building the last couple years. I've just deployed a major upgrade recently and to be honest am super happy that it seems to be getting a bit of traction.
You can’t beat hosting a plain HTML file on a static server here. You already have directory support with hyperlinks, and there is no Web technology today that will have more persistence when it comes to a template API. It’s as close as you can get to Just Works on the Internet.
Jekyll with Minimal Mistakes theme : https://mmistakes.github.io/minimal-mistakes/
Something like this Hugo theme maybe: https://github.com/LukasJoswiak/etch?
A lot of people seem to like https://bearblog.dev/
For me, bearblog & prose.sh.
Emacs Org Mode or Texinfo.
Hugo
Bearblog and Hugo
Permanence is my concern with the indie blog hosting services mentioned here (bearblog, prose.sh, nicheless.blog)
Also, because you already have a lot of the content, maybe you don't need a blog? what about a "digital garden" ?
What is a digital garden? -> https://maggieappleton.com/garden-history
Tools (easy options included) -> https://github.com/MaggieAppleton/digital-gardeners
If you have your content in a note-taking app like obsidian, there is even simple tutorials on how to freely publish it with all those precious "multiple tags per category", all in one go.