The fact that this has been going on for years, and that you feel the procrastination is holding you back from your full potential does sound like it could be ADHD, as others have mentioned. Also, ADHD tends to run in families. So if your dad is the same way... Most people associate ADHD with kids who struggle in school. But highly intelligent people can have it too. It still holds them back from reaching their poten…
I recognize a lot of what OP wrote and I’ve been working on it myself. I wasn't diagnosed with ADD or ADHD, but I was diagnosed with Asperger's (later in life, it wasn't even in the DSM when I was growing up). That diagnosis alone hasn't done much for me, psychologists don't have any clear-cut solutions for it, you have to work on it yourself. I don't think it's much different for people with ADD/ADHD, unless you like taking all kinds of medication with uncertain (side)effects.
Merlin Mann is taking meds for his ADD nowadays, but from what I can tell, he was working at it like a champ before that. 43folders probably couldn't have been made by anyone else, and personally, I love Merlin’s fast-talking meandering ways. Roderick on the Line and You Look Nice Today are my favorite podcasts of all time.