Seriously get on ADD medication. My friend suffers from ADD and severe depression. She went on Celexa and was able to function better and concentrate enough to get her work down. Her biggest obstacle isn't ADD or depression or alcohol, it's her extremely low self esteem.
What kind of a simple little job do you have in mind? I don't know about Europe but everyone I spoken to here in America regrets not going to school. They live pay check to pay check and work long hours. Esp. the immigrants here work really long hours with little money. Imagine working at a grocery store when you're pass thirty. It's terrible. I can assure you.
In my opinion, you should get medical and therapeutic help and stay in school, no matter what. The outside world, the working force is much cruel-er than school. I know this girl who never went to college and held the same job at a medical office since high school. Sure, it's okay now but what happens when the economy changes and she can't find another administrative job because she never got a degree? She will be competing against people who have work experience and a high academic education.
College is better for your imagination and creativity than the work force. Don't give up so soon. You haven't even tried yet.
Actually, maybe if you take a few months off and see how tough it is outside, you will want to go back to school and be much more motivated and focused. I never wanted to leave school but I did for reasons I can't control and trust me, working at a job that's beneath you, dealing with people all day doing mediocre crap, being paid 8 dollars an hour - it's fucking terrible. My only hope is that no matter what, I am going back to school and getting a degree, but not just that, learning and stretching my mind, my intelligence, my creativity. It's a blessing.