> I feel like a fraud, particularly when I get compliments or recognition at work. Yes, I am actually doing the work - it. But I know I could be far more effective if I could focus better. So I always feel like I'm only accomplishing a small fraction of what I could... and I expect people to realize that any moment now.
This is imposter syndrome[0]. Particularly feeling like a fraud, disassociation from compliments, and expecting people to find out you're a fraud. I think it's fairly common for some jobs/roles (software developers at Google, for example). I also think it's fairly common for people with ADHD.
You can still do more and do better (e.g. by better coping with your ADHD symptoms), that's normal and healthy to an extent. It's just that your self-perception is probably a bit too negatively biased. It's normal to have a negatively biased self-perception, but my guess is that your self-perception got warped a bit too much from decades of "sheer terror".
I can't really speak directly from experience with imposter syndrome, but what currently helps me deal with negative self-perception is acknowledgement and acceptance:
* cognitive reflection: Understand and acknowledge that many of my self-thoughts are negatively biased[1].
* meditative reflection[2]: Practice unconditional acceptance. Accept everything, accept my own performance, accept my negative thoughts of my own performance, accept my feelings of ineptitude.
... Unless "I'm only accomplishing a small fraction of what I could... I expect people to realize that any moment now" actually means that you expect people to find out that you're secretly really awesome and deep-down you're actually way better than all of them. That's probably not imposter syndrome.
[0] https://en.wikipedia.org/wiki/Impostor_syndrome
[1] https://en.wikipedia.org/wiki/Cognitive_distortion
[2] I don't really meditate per se regularly, I'm trying to illustrate that there are different ways to mentally reflect. Rational, logical, emotional, spiritual, whatever.