It seems to me that "Am I good enough?" "Is my writing good enough?" and "Is this particular story good enough for the market I'm aiming for?" are three very different questions. I know I tend to blur them all the time. I get a note that says an editor didn't choose to print a story, and I go from there to "I'll never get anything published" to "I can't write" to "I must be a sucky person if my writing is so terrible."

Not logical. But hard to stay away from.