When writing on the topic of writer's block, the words of Jim Butcher always come to mind. A highly admired author of urban fantasy novels, Mr. Butcher, when asked about writer's block, responded, "I don't have writer's block, I have a mortgage." After spending a while writing, and really getting to understand the process, it's hard not to agree.
Most people see writer's block as some sort of mythical stoppage of creativity; your tie with the muses has been severed, and you're left to fend for yourself in the barren wasteland of "bad writers." Nothing you put down on paper seems to work. Worse yet, you're having more and more trouble even coming up with something to put on the paper in the first place. The well of ideas has gone dry, and your mind is a parched desert where nothing can survive to make it to the page.
Lies and excuses. Self-deception at its finest.
Writer's block, in this writer's experience, is only real until a person decides it's not. Frequently, the cure is refusing to let the feeling that nothing you're writing is of any quality stop you from writing it. Author John Brown likes to call this approach "Farmer's Faith." If you put enough manure on it, something beautiful will eventually grow there.
If you're having trouble writing, there's a reason for it, and it usually has to do with a problem with your story. Maybe you've run into a situation that you can't seem to solve. Perhaps a character you've been writing has a difficult decision and you're not really sure which is the right choice for your story. It could be that you're having trouble making a solid connection between two parts of your story.
Whatever the case, the problem isn't that some invisible source of writing quality and wisdom has disappeared. The problem of "writer's block" can be solved in dozens of ways, the majority of which simply require you to keep writing. If it doesn't sound great, don't stop. Don't go back and agonize over your dialogue, or your character or setting descriptions. Move on, trusting in the process of editing after your story is done. A good writer understands that, with a very few exceptions, most writers don't get it right the first time. Some of the best writers that around don't even come close on that first run-through. Yes, there are the rare writers whose stories seem to fly off the screen and directly into your hand, with little anguish or editing involved. But these people are the exception, rather than the rule.
Take the time to ask yourself questions about what you're writing. What's really going on in this scene? What might the character see or do that you hadn't thought about before? Who could stand to benefit from taking control in this scene? What does the character truly want here? These sorts of questions, posed early and often when "writer's block" hits, will soon see you through to productive writing.
Start today. Make the commitment to break out of your self-imposed funk and put words on the page. You don't have writer's block. Your creativity isn't gone, it's simply been shoved aside by your lack of confidence in your first draft. Almost no one has great confidence in their first draft. This is completely normal. Sit down, put your fingers on the keyboard, and practice farmer's faith. Pile those words onto the page, and something beautiful will begin to grow.
A final word for writers everywhere: This article has done much to debunk the myth (as this writer sees it) of writer's block. That said, there is such a thing as depression, which some authors confuse with writer's block. If you feel that your troubles with the keyboard are anything other than a simple lack of farmer's faith, please seek help. There is no shame in getting treatment for a disease, and getting help now will certainly do more than improve your word count.