A self-care tip for people with brain fog that's saved me just now - document how to do stuff.
I'll sometimes get confused or doubt how I do something I've done a billion times. I'll forget logins, or which folder I've saved important documents I need.
I have a login manager that sorts out logins, pins, and passwords for me.
But I also really need and rely on a free wiki-style notebook (I'm talking about notion.so, but even notes app on a mobile work great if you create a tag or folder first) where I will create a whole page about something I need to manage, write down contact info, historic info I might need to make sense of stuff going forwards, where supporting files, receipts, or documents are (in the computer as links, or in the home as directions).
I have routines associated with it written down, and break down how I do things that I know I will get muddled with (for work, it can be something simple like "directing a new domain to a webspace on my server", "setting up targeted Facebook ads", or step by step tax returns a zombie could follow.
I'll keep records of spending and repair estimates so I don't get blindsided cos I forgot that thing happened this month and threw everything else off, or that the estimate was x but the repair took place in Y and that means it affects next month.
I will make step by step to do templates in something like asana or todoist (both of these allow almost infinite subtasks) so there's no thinking involved for important stuff on bad days. I use a timer while doing them following the templates and record the time, so I know that even on my worst day, It's never taken me longer than XX minutes to do this task. And that helps me manage anxiety about how long various things will take and therefore how much energy I need/ how many spoons it will cost me. That timer is the difference between me doing something today or this weekend.
Anytime I can't follow my own to-do template, I update it so it has everything I need to just click and action the next step. Some of the steps are as simple as "download this file", "copy it and save here". But having them as unique steps I can tick off really helps on bad days, because I can see a little streak of green checks and feel like "this isn't so bad, I'm doing it, look, I'm a quarter through already".