@Firstaide for this reason I have a bunch of self-checks I do every day, and record the result in a table in my Bullet Journal (which by the way is the single greatest life hack I've discovered for ADHD related difficulties).
All/nothing thinking could be tested with a thought experiment. Then you can be like "oh right I have low mood", recognising it for what it is and that it isn't permanent. When I recognise I'm having a bad brain time I can at least refrain from making any big decisions.