Most rejections are form letters: "Thank you for your interest, but your piece doesn't fit our publication. Best of luck." In 26 out of 75 cases, the rejection came with a more specific note; 23 of those notes were positive, with a few lines about what worked and didn't for the story and an invitation to send more. The other three rejections were negative. The one I received last weekend was particularly brutal, for a story that I felt was fairly strong (although certainly not without room for improvement, as is true of anything I write). And I'll tell you, that one scathing rejection hit me like a ton of bricks thrown one by one at my head.
Why does one piece of negative feedback affect me so strongly? As authors (and I suspect all creative people feel this), why are we so much more willing to believe the people who say we're bad at something than the people who say we're not? Yes: nothing we create is perfect. Yes: we can improve. Yes: the more we write, draw, compose, create, the closer our work will approach our intentions. I don't mean that we should indulge in false confidence, or ignore critical feedback. Sometimes it's right. There was too much exposition in there; that character did have almost no motivation; that story did end in the wrong place. But the next thing we create will be better than the last---every attempt is a chance to fall slightly less short of our goals than the attempt before.
Keep trying. Keep writing, drawing, singing, creating. Rejection, even when it seems personal, isn't as important as your desire to bring the things in your head out into the world. Remember, every creative person ever has faced rejection. Dig your way out from under, and keep going.