This sounds exactly like me. I'm about twice your age, and only realized I was ADHD inattentive a few years ago when I was trying to learn what to expect with my new ADHD diagnosed stepson.
Not letting down others is my biggest motivator. I'll let my life fall apart from neglect, but heaven forbid someone else become slightly inconvenienced! Sounds insane when you spell it out, but knowing is half the battle I guess.
Keep an eye out for toxic people.
It took me WAY too long to learn this, as I kept bending over backwards for people who would kick me when I'm down before they'd help me back up.
It's ok to just stay away from those people as much as possible. You don't owe them ANYTHING.