I have ADD/ADHD and OCD, so my attention span is very short, and I hate reading lengthy uninteresting information. I do not perform well under pressure (especially a TIME LIMIT). My favorite figure is Terence Mckenna. I am also very introverted and constantly philosophizing/thinking.
I'm sorry if this could be too pessimistic...
I have been in your position, 10-13 years ago, but I didn't even know that I had ADD, it was just too horrible for me to even try to get into some intellectual job as college professor or something like that.. I knew that, but I didn't know what/how to choose except for that.
If you don't want to think about suicide overtime the best thing you can do is get a good job that you don't dislike, and specially a job that would allow you to have enough spare time to develop your interests
on your own.
Otherwise you are going to find more and more frustrating conditions and you will realize how rotten and inhuman the "intellectual world" is.
I tell because I lived close to that social context, several friends of mine got into university, got their Ph.D. and post-doc stuff, and tried (succesfully) to get into Academy and other stuff.
All of them are "intelligent" but all of them are also very compliant, they are not subversive at all and not original, they just "flow" with everything that is needed to get into that world and they think "tomorrow I'll do what I really want, not today, because I cannot". None of them have ADD and none of them have any problem with reading long and boring books.
I'm talking about sociologists, politic sciences, philosophers, anthropology...
Maybe in your country the intellectual world is blossoming and there's different places or jobs that one could apply with your attitude and potential, what I can tell you it's that in my country (southern europe) that is completely non-existant if you don't think in a similar way to some political party or ideological niche, that's the truth...
probably in places like France that is a bit different, not here.