Or counterpoint- in my case I was helped at home a good bit with structure. It wasn’t until I was independent at uni that this facade started to fall off, revealing “issues”.
Decent enough in school but dropped out of college twice. Fell into an entry level IT job with loads of scripts, processes, and procedures but the more I progressed the more autonomy I was given and the worse I performed.
Was mostly terrible but occasionally amazing (enough to keep my job at least) for ~10 years then bumped into the ADHD symptoms at some point, got myself checked out, got the diagnosis.
Doing pretty well now (tho never perfect) with medication and a stint of cognitive behavioural therapy to help set up my own structure. Getting there!
I originally went for help with low confidence which expanded out to digging into and addressing self-esteem, confidence, social anxiety, procrastination, and perfectionism.
If I'd taken one general thing from it though it's "do I have evidence or is this an assumption?" - if I have no evidence (that I'm terrible at my job, I did bad, that guy hates me, etc) then I should reevaluate if it's even accurate before doing anything with the thought
Writing things down when things go wrong was a big part of it too - what's the situation, what led to the situation, is it possible to view the situation in a better light, if not how can I fix the situation, if I can't fix things myself is there anyone that can help me with this situation rather than wallowing in it. That sort of thing.
As I say I imagine it'll differ from person to person so other people may have an entirely different experience with it, I'm not sure. Definitely worked for my systems/coding flavoured brain though, really was like debugging faults in a program. Figure out the underlying issue, try a fix, did it work? y/n? If no, try another fix. If yes, work on the next problem.
Where are you? I can't think of a single place in Europe where medication alone is the treatment standard for ADHD.