Recently I got a rejection for a story I wrote, from a magazine I've submitted stories to before. Even though my story didn't make the cut, I was happy to hear back from them. There have been enough rejections in the past and they no longer sting as much.
Have a flower and take heart.
It's hard to hear that your best effort wasn't accepted. It's difficult to know where you went wrong when you're dealing with a form letter. But I promise, these things get easier. A few years ago, I read about a blogger celebrating rejection letters. They symbolized more than just failure, but the courage to try. I think about that a lot when I am working on stories. I've written a lot of things that may never be published. Photographs that I love and have labored over get declined for exhibition. It can take the wind out of your creative sails. It can make you cautious - too careful - when it comes to submitting again.
Please keep trying. Different places have different needs. Your work will improve with more practice, with gentle encouragement and with constructive criticism. You will evolve and no longer be so attached to each little piece that you create. Time does wonderful things for creative people. It allows you to build a diverse body of work, to examine past projects with a fresher eye, to rework and renew.
Still, rejection can hurt. I was not as hurt by this last rejection because I'd cried over the first one. This time I was just glad they'd gotten the story because their website submission system was acting funny when I tried to submit it. It's funny that this reject was a comfort, because I knew they'd at least gotten the story when I'd been afraid they hadn't. They read my work, and though it wasn't right for their publication, it might be right for another down the line.
Don't give up friend; rejection may be part of the process, but it doesn't define it.