Creative writing

I've been experimenting with RAGs logic/javascript, graphical overlays and writing over the past couple of weeks to help the creative juices flow. Of the three parts required to make a game in RAGs (excluding the 'optional' design part), I definitely find writing to be the most difficult part. I don't know what it is, but I've always struggled to write. Whether its creative writing, technical writing or basic communication I always agonise over the choice of my words and end up being very concise, which is the antithesis of descriptive writing!

I've been reading a book on creative writing to try and improve that area. The book talks a lot about identifying themes, character traits and so on which I understand very well. Unfortunately where I fall down is converting the concept into actual prose. I agonise over the sentence structure and word choices, never feeling confident about what I do manage to write down. My perfectionism ends up paralysing me because I have no idea if I'm even close to having something 'good'. I got top grades in English at school, but I'll be damned if I know a single thing about it.