I think I have ADD, how should I bring it up?

I have ADD also, it's really not a big deal. I think you are maybe just over-reacting. Why tell people. It's not like it will make a differance. When you meet someone or are in a deep conversation do you really think they'll want an explanation for losing your phone or why you didn't copy all of friday's notes? No, they won't. Beleive me, it's alright, once you get used to th idea, you won't even care anymore.