Here is an excerpted version of Joseph Conrad’s letter to Edward Garnett, 29th March. 
“My Dear Garnett.
I am ashamed of myself. I ought to have written to you before, but the fact is I have not written anything at all. … I sit down religiously every morning, I sit down for eight hours every day–and the sitting down is all. In the course of that working day of 8 hours I write 3 sentences which I erase before leaving the table in despair. There’s not a single word to send you. Not one!… sometimes it takes all my resolution and power of self control to refrain from butting my head against the wall. I want to howl and foam at the mouth but I daren’t do it for fear of waking that baby and alarming my wife. It’s no joking matter….So the days pass and nothing is done. At night I sleep. In the morning I get up with the horror of that powerlessness I must face through a day of vain efforts.”
Joseph Conrad was an outstanding and prolific author who published scores of stories and novels. But as you can see from the above quote, he also had prolific struggles with writing. He even used the word “horror” in his letter about being blocked; a word that later became repeated as the infamous Mr Kurtz’s famous last words in his novella The Heart of Darkness. OMG! Is this book a writing block allegory?
A willingness to deal with the darker corners of the human psyche is an asset for a writer. Conrad had excruciating episodes of despair and agony while trying to write, but curiously, he did not give up. Somehow, he seems to have tamed the beast that would devour him, and harnessed it in the service of his craft.
When the inner drive to write is strong, as in Conrad’s case, then blocks are experienced as especially agonizing. A fierce drive to create does battle with a fierce inner resistance and the writer’s mind and body are tested to the limit. When the artist is victorious, and writes his story despite the inner storms, his story has to feed on that struggle somehow. The question emerges as to whether some of the stoppages and pauses that writers experience are in fact integral aspects of, as opposed to departures from, their creative process.
In one way or another, you meet yourself when you write, and sometimes the self that greets you turns out to have some scary, dark edges. These are the times when the your writing is at risk to grind to a halt, because the emotional intensity is hard to tolerate.
Take a deep breath, and take some comfort in the knowledge that encountering these dark parts of your heart doesn’t mean you are doomed to become a meglomaniacal jungle butcher. You can write a good story about that instead.