Rejection is an ugly beast that you have to confront many, many times in your writing career. How you defeat it and hush its monstrous roar is up to you. I calm mine with loud music I can’t help but sing too, like Adele.
Maybe yours is a walk, or a gallon of cookies and cream ice cream. Whatever it takes to put your beast to bed, do it, then wipe the ice cream dribble off your chin and get back to writing.
Rejection’s only rejection if you quit.
And we don’t quit.