Mark O'Connell writes a long piece on self-doubt in the literary mind:
Because if I had to identify a single element that characterizes my life as a writer, a dominant affective note, it would be self-doubt. It is a more-or-less constant presence in everything I do. It is there even as I type these words, in my realization that almost all writers struggle in this way; that the notion of a self-doubting writer is as close to tautology as to make no difference, and that to refer to such a thing as a “struggle” is to concede the game immediately to cliché, to lose on a technicality before you’ve even begun.
I completely identify with Mark's assessment here. I tend just to blunder onwards despite my misgivings.
To put it in the sort of simplistic terms that I’ll no doubt come to regret using: self-doubt is the best friend and the worst enemy of the writer. Because being a writer isn’t like being a tennis player or a boxer, where you presumably have to hunt down and ruthlessly eliminate the source of any flickering shadow of suspicion that you might not be destined for victory. As a writer, you have to take your own misgivings seriously; you have to attend, now and then, to the little voice in your head or the booming baritone in your gut that wishes you to know that what you are writing is entirely without value.
Wil Wheaton discusses something similar in his post on imposter syndrome here:
Part of having Imposter Syndrome is believing that people who praise you are dupes, while the people who criticize you can actually see through everything. But the thing is, the guy who isn’t thrilled has every right to feel that way, and I don’t take it personally. Not everyone digs what I do and what I bring to a project, and that’s totally cool. At the same time, it’s also pretty awesome that a lot of people do dig what I bring to a project, and that is also cool.
Read Marks' full NY Times article here: http://www.nytimes.com/2013/12/08/magazine/the-dutch-elm-disease-of-creative-minds.html