I have ADHD. I can usually hold my shit together at work, and I work 16 hour shifts. Some days my coworkers will notice enough to ask me if I've taken my meds, but most days I appear pretty chill. I'll bet if you asked the majority of my coworkers they'd tell you I'm not ADHD.
What they don't see is me going home and sobbing on the floor from the sheer effort and desperation of trying holding my shit together and not fuck up in ways that I can't fix. I'm terrified every fucking day that today will be the day I fuck up enough that I can't hide how bad my brain actually is anymore and I'll make a critical error and I'll lose my job. I don't have a backup plan or someone to catch me if I fail, I'll just be homeless at the end of the month when I can't make rent.