From Longman Dictionary of Contemporary Englishget a gripget a gripspoken used in order to tell someone to control their emotions For God’s sake get a grip! → grip
Examples from the Corpus
get a grip• Pet could, but Wee Charlie ... Get a grip! she admonished herself, dashing her tears away.• I remembered my first time, my trembling hand and Big Frank Connell hissing Get a grip.• Why was he shaking and breathless on the corner of some disgusting back street? Get a grip on yourself, Benjamin! 