You have attention deficit disorder (ADHD or ADD). This is not the most tremendous news. But, in some ways, a diagnosis can bring relief. Now you know what's been going on all these years!
Maybe you've grown up with people calling you lazy, sloppy, or unmotivated. Maybe you've spent your whole life feeling like you weren't living up to your potential, or you could only function when you were doing something you enjoyed. You beat yourself up about not following through on details. Now, a diagnosis is proof that what you're experiencing is a biological, brain-based condition – not a moral failing on your part.
[Self-Test: Could You Have an Executive Function Deficit?]