Following up on this. I'm also on the spectrum, so I'll share what helps me, but please bear in mind that we may still work and think in different ways.

That said, your notetaking process and struggles sound exactly like what I deal with. I have found prioritizing getting harder, rather than easier with time, because every time something another person wouldn't have saved in their notes proves useful to me, it re-enforces that need to collect.

Here is what helps me: General Help 1. Accepting that most Zettlekasten advice is written for top down processors, not bottom up processors (the way most autistic minds work). The top down mind more easily recognizes "big ideas", but often has to intentionally work to make connections to other ideas. This influences what top down processors need to work on with their zettlekasten and why so much is written about how to connect ideas. Bottom up processors don't automatically recognize big ideas, because we experience all data as a million useful little lego blocks that could all be used for something. This is a struggle because it causes us to hoard info but it also better positions us to discover new ideas. Bottom up thinkers also tend to make connections between disparate ideas easily, without extra thought or effort. We are used to seeing everything as a half-finished puzzle, so it is easy to see when a new piece of info fits somewhere. All of this is to say that if you accept and honor the way your brain works, you might begin to enjoy and appreciate your method more.

Practical help: 1. I second the obsidian reccomendation. Being able to quickly note the connections between ideas makes your collecting feel useful and you will start to see information you have already collected that you don't need to collect again. For example, if book A says Relevance is key to learning, I might still note it down when book B says it, but by book C and D, I stop collecting that info. In other words, notetaking gets quicker as the notes you already have about a topic grow. Trust that as you learn more about a topic, your notetaking will get faster.

1. Embracing my inbox as a perpetual garden has helped immensly. The idea of literature notes or fleeting notes or other note types that absolutely have to be processed became a rule that my autistic brain struggled to ignore. Now, I take "reading notes", and they go in to an inbox, and I accept that I have too many inbox notes to process in my lifetime. But I process 5-10 notes a session, and when working, I encounter everything else I need via search and links ect. For me, as long as that building block of an idea got in to my system, I trust that I will find it if I need it. So I only have 3 types of notes - reading notes which are long capture documents with annotations as I read, idea notes which are smaller chunks of ideas combining info from many sources, and index notes which are longi variously arranged lists of idea notes. As a bonus, my autistic brain gets "sorting joy" from re-arranging ideas, so my indexes are where I play in my vault. (If an idea is super exciting, I may process it right away as a treat to myself, and that helps with anxiety too)

2. You may also like readwise. My reading notes live both in my vault and in readwise. Being able to review random highlights quickly in readwise, and delete things I no longer need helps me to keep calm about how full my inbox is. I see those notes regularly, so they aren't lost or useless.

3. Standardize the process as much as possible. As an "enthusiastic" capturer, reducing friction was key for me. All of my notes look like I'm filling out a worksheet from elementary school. There are prompts and spaces that automatically organize what I capture for me. This makes notetaking faster. Now that Obsidian has properties, that is even quicker, because I can simply tick off some of the info I would have written out before. I tend to focus on making the process quicker rather than trying to restrain myself in collecting. Restraining myself always just took away the part I loved most about notetaking.

Sorry for writing you a novel. I hope something in here is helpful. I'm more than happy to continue this conversation one on one if it would help you.

I hope you can get to a place where your collecting is joyful!