PKM Personal Knowledge Management

Hallo, Hello, Hola, Aloha, etc.

I kept notes for a five year-long D&D game in Microsoft OneNote, which worked fine, but I kept wishing for more features. I'm hoping y'all can recommend something better suited to my desired use.

• Page per game session (day), unless there's a better paradigm
• Crosslinking easily, so that I can link every appearance of a character in the notes to a page for that character (or spell or place or organization or whatever). Is it possible for this to happen automatically by linking future uses of that word?
• Some stats about frequency e.g. "this character has appeared X times" or "player X rolled a 1 Ytimes". Probably achieved by counting the number of times a page was linked to?
• Ideally, but not mandatory, collaborative. I'm capable of self-hosting either full time but maybe some have a "share on local network" option to use during a session.
• Inserting images
• Open source is preferred for ethical reasons, but I can use proprietary or paid software
• Don't care much about text formatting

I appreciate any input!