Yes, trying to follow standard organisational, motivation or prioritisation type advice often won't work because it's designed to work with the neurotypical brain process. ADHD (especially unmedicated/unmanaged) means that some of your reward and motivation pathways aren't working the same, and your executive functioning is impaired. So some NT advice will fall flat.
When we come across these methods and try them and they don't work we then often turn that back on ourselves and feel like we have failed. But the analogy about using right-handed scissors if you're left-handed is a good one.
Here are some "left-handed scissors" that I've found:
How To ADHD (youtube channel, various topics)
A Slob Comes clean (cleaning, organising, decluttering, household management, habits)
Struggle Care/KC Davis (various topics)
College Info Geek (youtube channel, mainly motivation, some health/mornings/productivity)
YNAB (budgeting software; unfortunately not free)
Tody (cleaning/recurring tasks app)
ChatGPT (ask it to suggest tasks, help you prioritise a to-do list, write a daunting email, write a script for a daunting telephone conversation, break tasks down, help motivate you, probably a load of other things)
ADHD Essentials (podcast, various topics)
The Anti-Planner by Dani Donovan (expensive but good - an app version would be good)
Weirdly, Marie Kondo? But you have to actually read the book and do all of the steps, not just follow the internet idea of what this is, which misses out a lot of steps that are important for an ADHD brain.
The concept of a "dopamenu" (google it - helps with motivation)
And some general principles.
If a self-help method or advice consists of just convincing you why the thing is important and that is the extent of its motivation tactics, this won't work. Instead of a method that tries to tell you why something is important, find methods that tell you how to make things easy or fun. Methods for children often work quite well.
Being able to easily get back into something is more important than consistently doing it every day forever. Embrace short cuts.
Instead of shame, blame, or reinventing the wheel, look for the barrier and solve that problem.
Break big, far away results into small, measurable bits of progress with instant feedback. (e.g. Couch to 5k is better than just a vague "I'll go running" because you can see yourself progressing through the program and your pace getting faster, etc.)
We tend to be highly motivated by connection, probably because it provides dopamine, so tell people about your goals, join support groups, MN threads etc. Signing up for some kind of class or commitment is also more effective than saying you'll do things on your own. Some people find body doubling effective (the thought makes me cringe, I don't know why!)