Serious speech problems? what is wrong with my tongue?

I know i have a case of ADD, i have problems following directions or orders, although i understand at the end, you have to repeat it to me until i get it, i get kind of scared when someone is talking to me cos im afraid i wont understand, i understand things with a delay, for example you say something to me and then like a few mins later i get it, it happens sometimes like in jokes or other topics, i have unfinished bussiness, i lack concentration sometimes, my tongue kind of gets stuck when i try to explain myself, like i have the idea in my mind but when i transform them in words it comes out with no organization at all, i want to express something but my mouth cant, then i say wrong words or say it with wrong grammar, also, i do repetitions, i repeat something twice, like someone asks me ''where is the umbrella'' i said ''its in the bag, its in the bag'' , in a phrase i repeat it twice, and fast and i kind of stutter, i get scared when someone asks me something im afraid i wont say something with sense, therefore, writing i can express myself perfectly, whats my problem?