None of us can completely separate our feelings about our “self” when judgments are made about our writing. But perhaps we can move in that direction just enough to prevent criticism and rejection from paralyzing our writing muscles. One way to do this is to keep asking, “What will help the writing?”
You will benefit more if your mind is focused on that question rather than on whether or not you are an imposter or an idiot or stupid or worthless or boring or magnificent. After all, our lives are a mystery—we don’t really know what is going on, and all the time we spend protecting, defending, rationalizing, loathing, and lauding our sense of self is, at the end of the day, a pointless exercise in generating pain. Maybe it would be better to spend what precious little time we have on the planet doing anything else instead of that.
By keeping your primary focus on how to make your writing better, rather than on how criticism and rejection make you feel, you also cultivate a degree of openness and tolerance for receiving important feedback that is not complimentary. It is essential for your growth and development as a writer to be able to take in such information without wilting completely.
The perceptive minds of others offer a storehouse of information, and you can benefit from knowing what they think is good, or not so good, about your work. Even some nasty, ill-tempered remarks will potentially be useful to you if they contain a grain of truth. You will be more willing and less threatened to hear tough but true words about your work if you believe those words will help you write better. Even if they come from the mouth of a jerk.