From Longman Dictionary of Contemporary Englishit’s not the end of the worldit’s not the end of the worldspokenSERIOUS SITUATION used to tell someone that a problem is not as bad as they think → end
Examples from the Corpus
it’s not the end of the world• You won't always get it right, but it's not the end of the world if you don't.• It's very upsetting, but it's not the end of the world.• If you don't get the job, it's not the end of the world.• All I've done is offend one or two of the wrong people, it's not the end of the world. 