Last night I was a part of a writer's forum in which we discussed why people don't submit their manuscripts. What it boiled down to was confidence, or, more properly, a lack of confidence.
I let the group know that I don't believe this issue ever really disappears for most writers. I know it hasn't gone away for me. Instead of waiting for "more confidence", as someone said, I urge you to, as the shoe commercials say, "just do it."
Consider: what do you have to lose? You know it won't get published sitting on your computer. Send it in anyway. Forget about the manuscript being perfect - as long as it's not sloppy, dirty or poorly assembled, get going!
Just some thoughts...