I was actually pretty fearless when I first started back in 1999. I felt slightly embarrassed at my less than pro art (completely oblivious about how dumb my writing was, heh heh), but it wasn't fear. The joy I got out of drawing and sharing always outshone any negative feelings I felt about my own work. The artist/writer in me didn't even know the meaning of the word 'fear' until some time last year, months after my current webcomic has been running.
When Fear finally arrived, it wasn't a nagging feeling... it replaced my world. I was like a pathological anorexic obsessed with "gotta get thinner," except it wasn't about my body. It was about my comic. The rest of my life ceased to exist for over a month until I finally realized that this wasn't normal, that I was ill in the mind. Since then, I've been recovering. The path to recovery has not been a straight upward road; it's an upward spiral, making it seem like I'm going in circles, but looking back long term, I know I've made huge progress.
Hang in there, man. This irrational fear is what DESTROYED me last year. I was somehow convinced, beyond ALL doubt, that failing to make my story good enough would mean the end of my life. It makes no sense, but I didn't even think to question it at the time.
But as it turns out... I'm still here, alive, even though my writing sucks almost as much as it did last year! \o/