"You have to know how to accept rejection and reject acceptance." --Ray Bradbury
Except for career masochists, nobody likes rejection. We love to be loved, to be appreciated, to be lauded for our efforts. And writers, especially, love to be praised for their work.
Unfortunately, the universe doesn't always work that way. Our manuscripts get rejected, we lose freelance clients, others get hired for the jobs we want. How to deal with this?
Of all the possibilities, the right steps involve moving forward. Continue to write. Keep submitting your manuscript to appropriate publishers. Hone your skils, polish your resume, make those professional connections count. Take classes. Read. And, above all, write.
Don't give up. Don't give more weight to outside opinions than you do to your own. Don't let past stumbling blocks permanently impede your progress.
Believe in your talent and in what you have to contribute. Maybe you need to try a different genre. Maybe find a new niche. Maybe all you need is a change of surroundings, a new outlook, a fresh perspective.
There are so many things to try to get through to writing success.
You only fail when you quit trying. And that's a wrong step in the "write" direction.