Our minds buzz a million miles a hour all the time and we can't help it. It is our gift and our curse. I always look at it this way and you can quote me.
" The best time to write is at night. All the good thoughts have not been recognized yet. People are either asleep or too drunk to have a sane thought."
I am my most creative at night and I wish I could stay up all night writing. Its like my brain comes up with these magnificent ideas and because I am a wee bit tired, my brain shuts off the filter. The result: pure unfiltered genius. Thinking kills writing. Thinking is self conscious. Just do it. You can fix it up and edit it beautifully later. Late hours are the hours for the genius' to work their magic.