What you might perceive as late-onset ADHD could be the cause of not being able to keep your coping mechanisms up due to stress? In my case, social anxiety (which I'm officially diagnosed with, but not ADHD) skyrocketed after a series of family events, which resulted in not being able to focus on anything mildly difficult or anxiety inducing, as my mind quickly started wandering out of nowhere, and becoming aware, shutting it off and getting back on track is really difficult. My anxiety medication is really helping, alongside therapy, and I feel way more in control, but not like before