Close your eyes and think back to your childhood. What were you afraid of? The dark? Monsters under the bed? Or was it something much more real, more tangible? Spiders maybe?
Grab a piece of paper and write about what you were afraid of as a child. You could write a poem, a short story, whatever you feel like writing. Take that fear and run with it, embrace it. Deal with it.
When you're done, feel free to either keep what you've written, or destroy it if you wish. Maybe writing the words down only to set them on fire so the ashes can float away is what will finally banish the fear forever.