If you want empathy, you got it, haha. I too have ADD, and it is SEVERE. I've had it since I was about five years-old, and it pretty much ruins your life if you don't get treatment for it. I take meds for my ADD but it only helps so much. And I totally sympathize with you when you say you can't complete a project - almost nothing in my life has been completed unless I've HAD to do it. Looks like more meds for my ass, haha.
I too am interested in many aspects of the industry, game design, art, writing, I can do some programming, but I'm a VERY right brain person so that wouldn't suit me. And I'm with you on the team thing, it's especially hard when you're not a very outspoken person. I'm assuming you're a reserved kind of cat too, my advice is: We're just gonna have to put up with the team environment. Normally, I'm one for advocating to strengthen your strengths instead of strengthen your weaknesses, but the team environment is a huge part of the industry from what I hear, and if we want to make it in the field, we gotta suck it up. Can't make a hit game on your own. Well, I guess you could, but it would take a looooong time. I know, it sucks haha.
I can imagine you don't have it as bad as me because you can actually start a game project. I probably can't give you any good advice because I'm in a similar position, but hopefully my horrible ADD will make you feel a little better about yourself.