You love making programs that reveal yourself as a programming god. You produce results that demonstrate you are, quite obviously, the greatest scientist of our generation. You show these to everyone in your office/corridor/family, they all appreciate your magnificence. After a few talks at conferences comes the bit you've been avoiding - writing everything up.
I think I'm fair in saying that you went into bioinformatics for something other than writing reports and papers. At some point though, you have to.
Set a daily goal
When I have to write, I set a goal of 500 words a day. Even if they are complete nonsense, which they usually are. Writing, like everything else, gets better with practice. My writing usually becomes more coherent, the more I do. Once you've got everything written, even if it's rubbish, you'll feel much better. You can start editing for clarity later.
Throw away as much as possible
You've written huge amounts of text, so why bin all the effort? Because you're writing for other people. Everyone one has to expend energy to read your work. Think about how dull it is for you reading badly written text. It's a boring activity that you have to force yourself to do. Now what if the document had instead been composed with the reader in mind? The point is put across in clear and simple terms. Every paragraph, sentence, word is there because it has to be.
Learn how to write well
Writing, like presenting, is a skill that doesn't receive as much attention as it should. Particularly in science where, quite rightly, the emphasis is scientific method and ability. But once you have your results, you need to communicate them. I've found that becoming better at writing makes you more confident, making writing more enjoyable and a less arduous task. To this end, I recommend Strunk and White, "The elements of style". Fortunately, this book is also available online. Also check out this page for a practical introduction to writing.
Finally, if you're taking one thing away from this post, please take this.
Vigorous writing is concise. A sentence should contain no unnecessary words, a paragraph no unnecessary sentences, for the same reason that a drawing should have no unnecessary lines and a machine no unnecessary parts. This requires not that the writer make all his sentences short, or that he avoid all detail and treat his subjects only in outline, but that every word tell. William Strunk Jr., Elements of Style
Forty two words were thrown away in revising this post.