A close friend of mine in graduate school was working on draft of an article and told me "Y'know, right now, as far as writing goes, all we can really produce is a turd. And it's our advisor's job to take that and work with us on it for a couple months, and if we're really lucky, by the time it's done, it'll be a well-polished turd."
Sage advice. One of the greatest tools in the writer's toolkit is humility. If you can find some peace in your soul and write something you know is horrible, and just trust the process, it gets better over time.
Also, I recommend looking up "The Most Dangerous Writing App." If you want a tool to help you with the fast writing, it's very hard to do better than that one.
J