The phrase 'Pull Yourself Together' means to get control of your emotions and actions.
Example of Use: "He's finding it hard to pull himself together after the accident."
The origin of the idiom 'pull yourself together' isn’t known for certain. What is known is that its meaning is closely related to that of another popular idiom, 'mind over matter.' 'Mind over matter' is a very old idiom – it was used in 70 BCE by the poet Virgil, in his poem The Aeneid.