"If you're not prepared to be wrong, you'll never come up with anything original."--Ken Robinson.
I was watching a short video about schools and learning processes by phenominal speaker Ken Robinson (http://www.ted.com/talks/ken_robinson_says_schools_kill_creativity.html) when he made the above statement. I jotted it down and read it several times, letting the truth of the words sink in. I encourage you to do the same. The statement is profound for every one of us, but especially those of us fearful of taking chances.
Try to write without fear and filters. Or at the very least, don't let those things inhibit your writing, or curb your ability to let creativity flow. It sounds like a no-brainer, but it's surprising how our own internal filters (or neg. and fearful voices) can hold us back. Write with freedom and abandon, let it pour out of you. Filters, or editing, comes later. First create, then shape. But through it all, keep the above quote close at hand.