Motivational guru and success expert Napoleon Hill (http://naphill.org) said, "You can't control others' acts, but you can control your reaction to their acts, and that is what counts most to you."
That's sound counsel for life generally. Only you control your emotions. No one can make you angry, fearful, or inferior or make you react in any other negative way without your agreement or permission. But you can choose to respond positively. And that's what separates the mice from the men, as the saying puts it.
But this wisdom is also good for those of us who are writers. We often allow negatively responding editors, reviewers, or critics determine our outlook and self-concept. But we shouldn't allow such "nabobs of negatively" (as an infamous former vice president was fond of saying) determine our attitudes for us.
For example, whenever we receive a rejection of one of our submissions, we must not be hard on ourselves and thereby allow one person's opinion to set the tone of our day, week, or even career for us. If you've read this blog very long, you know that I've repeatedly stated that rejection is part of the writing life, just as striking out is a fact of life for every baseball player. For every writer, even big-name authors. (Perhaps those big names don't get rejected as often as we lesser known writers, but they still get rejections.) Therefore, we should accept rejections as just part of life. Acknowledge that the piece didn't fit or suit that one editor's taste or needs, but that doesn't mean it's a rejection of us personally, of our writing generally, or an indication that we don't have what it takes to succeed as writers.
Quite often, I suspect, editors and reviewers and critics are people who envy you, the writer. They would like to be successful authors themselves, but they often aren't. They often are wannabes. Perhaps they've tried but given up, and so they've settled for what they consider the next best thing, they're editors or reviewers or critics. I wonder how often someone who writes a scathing review or offers nothing but negative criticism about a book secretly wishes that they had written that book.
Regardless of why an editor rejects your manuscript, or a reviewer pans your book, or a critic excoriates your writing, if you're following your calling, dust yourself off, get back up, and go at it again. Learn whatever you can from the negative responses, but keep on improving, learning, and writing. And let the chips fall where they may.
You are the only one who can control your reactions. Start controlling them positively. That's one of the marks of a successful writer.