Idiom: Pull yourself together: used informally
Context #1 Coach and player talking
Coach: Ok, this is really an important race. If we win the next race then our team will be in first place.
Vinnie: I know coach but I'm so nervous. I don't think that I will be able to compete. I think I'm going to be sick.
Coach: Come on..... pull yourself together. You have run this race many times and you have always done well.
Vinnie: Yeah, but I feel so sick.....
Coach: Come on and do your best.
Context #2 2 Students at an ESL school
Meaning:This phrase is used when someone needs to calm down and to control their emotions.
Kenji: Oh dude I forgot that we have a test today. I'm going to flunk it.
Mai: How could you forget about this test. We have been talking about it all week. And I'm sure you won't get an "F".
Kenji: I know. What am I going to do?
Mai: Well first you gotta pull yourself together. Freaking out isn't going to help you. I'm sure you will do well. Remember it's only a small percentage of our final grade.
Jenji: You're right. Any grade is better than a zero.
In context #1 The racer is worried about loosing the race and disappointing his coach and team.
His coach tried to relax him and remind him that he is a good runner.
In context #2 Kenji is upset because he forgot about a test and is worried about getting a poor grade.
Mai gets Kenji to calm down by reminding him that he is a good student.