Rejection leaves things as they were. Suppose you ask for something and the answer is no. Then you have exactly what you had before you asked.
The fear of rejection is much worse than rejection itself. Someone who hasn't been rejected a lot hasn't tried very much, has played it safe most of the time.
Rejection is not a stain on you. If you read poems in a literary journal you will read what is there, not what isn't, so nobody is thinking about your rejected poems.
You can think of rejection as a percentage. If you had to sell 10 tickets to an event you might have to ask 500 people. Then you've met your goal. I'm going to submit poems every day of the year that I can. I just have to have a few acceptances out of all of those. If I want 10 poems in print I might have to send out 500.
Rejection isn't personal (except when it is!). There is such a thing as personal rejection: someone is rejecting you, as a person, does not want to be your friend or romantic partner, or even to do something with you. That is a topic for another post. But a lot of rejection has nothing to do with one's self. Say you send in an article and it is read as a blind submission. Even when there is some personal element, it is helpful to realize that it might be less of a factor than you assume.
There are people who have been rejected in traumatic ways, or for whom rejection is the dominant experience in their life. Those people won't be able to view rejection in the way that I am recommending.