You're probably familiar with the myth that drugs and drink "stimulate creativity."
I think the myth confuses "creativity" with "nerve." When a man has to get drunk before he dares to approach a woman and talk to her, he might tell himself and others: "Alcohol shtimulates my libido!" But his real problem is, he's afraid. And we know what alcohol really does to the libido.
The issue, then, is fear. Fear of failure, fear of rejection, fear of imperfection (the most paralyzing of all anxieties), fear of ridicule. Writing skill is a combination of abilities, but losing your nerve can wreck your writing life completely.
It fascinates me how individuals are prepared to risk their health in the most reckless manner possible - drunk driving, bungee jumping, walking on the edges of rooftops, paintball fights... but ask them to read a speech (or sing a song) before a live audience, and they freeze up with terror.
Talk about keeping your priorities straight! :)
Ditto with writing fiction: would-be writers and active writers alike are gripped by paralyzing fear. What to do?
I'm no psychiatrist... but why not try this:
1. Write under a pen name. If you're afraid of having your name associated with (and shamed by) your novel, use a pseudonym. Like a clown mask, it provides a measure of ego protection. And in any case, "Rex Mackenzie" is a cooler writer name than "Melvin Poznovski."
2. Regression therapy. Imagine yourself as a kid playing with crayons or Lego. You're eight years old, and you write. See what happens. (Then grow up. You can't remain a child forever.)
3. Listen to really loud rock music while you write. It works for others. It can work for you. (Be careful so you don't damage your ears, though.)