ADHD/Writing

Oh man. My dream in life has always been to be a writer. ADHD has always made this, and almost everything else in my life, difficult. I sit down to write and I start to flip out. The thougts in my head are all jumbly (for lack of a real word that is as fitting). I seem so clever in my head but when I begin to write my thoughts and arguments no longer seem so certain.
I get really irritable -too. Any sounds in the house, like if someone starts talking, I am ready to pounce. It is as if my mind doesn't have enough juice to breach the barrier between my brain and the paper.
I do find though the first day I am frustrated...the second day I sit...less frustrated...the third...even less frustrated, until eventually I get something written. And if I can just sit in the spot for like a half an hour before I begin writing, the words flow a little more too.
I always feel upset because I can't believe that something I want so much could be so difficult. So many times in my life, I have given up on writing, only to find that really I can't let it go.
I hope that the good Lord is up there watching over me and that he sees that I am really trying to do the right things. I do believe that if I make the first step, the Lord will multiply my efforts.