I don't know anymore

"I am an Artist. My medium is unseen, but I am one all the same." - The last of August, Brittany Cavallaro

I read The Last of August a couple of months ago now and I can't seem to let go this qoute. I feel as though I completely understand what it means and at the same time I don't. I often have this same affliction in most parts of my life, as though I have all of this creative build up that I was to spew onto a big unknown canvas with an unknown medium. I lose faith in myself and in my capabilities and it's terrifying. Somedays I don't think I have any capabilities to do anything spectacular. I'm scared I'm scared I'm very scared.
 All of the time.