>I have strongly come to perceive myself as being driven by external accountabilities
These are classic ADHD symptoms, along with some of the other tells I've gotten from your description. The number one way to improve ADHD symptoms, by an enormous margin, is through stimulant therapy. If this kind of pattern happened a lot in childhood, and you have a history of other related issues (losing homework, procrastination until deadlines, high caffeine use), then I'd highly suggest scheduling a meeting with your mental health provider about this and getting a diagnosis.
And again, it's quite hard to overstate how effective stimulant therapy is for treating ADHD. It's the most effective mental health intervention. For me personally, it makes a night-and-day difference.