It makes perfect sense; an obsession makes it easy for you to focus on the subject of obsession, and hard to focus on other things. As school likely mainly consisted of things other than programming, an obsession with programming would naturally adversely impact overall focus at school.
For example, It doesn't sound like you have ADHD. A classic symptom of ADHD is the ability to hyper-focus on one thing, to the exclusion of anything else. Such as being stuck so deep into a book or project that you'd barely notice if the building was burning down. Any sort of school/life balance would be extremely difficult to achieve.
Because when it's time to study biology, all one thinks about is how to distribute units of work across GPUs for that thing they're working on. Kind of like the two pit bull terriers I have at home. Oh, they can focus like a motherfucker. Too bad that when they're focused on a squirrel they have no bandwidth left for my commands.
This I get. One of the hardest mental blocks that I had to get around was thinking that it would be deeply embarrassing and triggering if I talked about my decisions and experiences. That I would be "found out" and "be exposed as a fraud".
It is quite the opposite. Talking about your experiences is extremely liberating. You can be who you are, you don't have to make anything up to fill in the gaps, and it is just in general much easier than worrying about conforming to some expectation. AND you will be much more interesting, because you have lessons to pass on that somebody else may find valuable and apply to their own lives.
Don't you think you should probably stop your activism? It isn't good for you and you're in no position to advocate for anyone.
I would caution you not to. What goes on the internet stays there forever. Google will fight your right to be forgotten. Real names are a great way to attract batty twitter haters who want to ruin your life due to some perceived slight from reading your stories. You can easily go from pity story of the day to "ZOMG I hope you never get a job and die in the streets" in just a few words on this board. Be wary.
"My interest in computers and programming was more like an intense obsession. It affected my ability to focus at school." <- this makes no sense. To me, programming is an exercise in formulating a plan, executing the plan, and verifying the outcome. Every step requires focus. How do you "study" and "program" without being able to focus?
"Undiagnosed mental-health problems led to some fairly poor decisions." <- what health problems? what decisions?
"Relationship issues for a now twenty year old developer proved to be too much. Emotionally I was devastated when that relationship ended. It affected me and I had no one to help me through the emotional stresses of the situation. It affected my work. It affected my activism." <- Every sentence here is interesting. If he went into detail and wrote about this, it would fit the title and it would grab my attention.