There are plenty of sayings I could link to falling down and getting back up again, but we've all heard them. Probably so many times that they no longer carry the same weight.
I took a literal tumble yesterday down about eight cement steps outside my office. Yeah, ouch. Luckily I didn't do anything more than earn myself some bruises and scrapes. But, naturally, it had me in a contemplative mood all night. Because that's just how I am. Always trying to find the lesson, the deeper meaning to things. ;)
There are more than the physical tumbles and falls we make over the course of a lifetime. Especially as a writer. One day we may be flying high on the devotion we feel to a project, and a rejection letter later -- well, we're face first on the pavement writhing in pain.
Dramatic example? Yes, but it paints the picture.
Over and over again we may tumble and fall over the course of our writing careers. It may be breaking into the market that proves most challenging, or it could be that tenth novel you can't get just right. Whatever your place in this community, we're all gonna stumble and fall sometimes. The important part is to reflect on it, to learn from it so that the experience will make you stronger.
And it really will. While rejection or a critique may hurt, they will only make you a stronger writer in the end. So get up, dust yourself off, and reassess the situation. It's okay to wallow for a while, and by all means cry, but then get back to work and make it better.