be out of your element
From Longman Dictionary of Contemporary Englishbe out of your elementbe out of your elementRELAXEDto be in a situation that makes you uncomfortable or unhappy She was out of her element in this dull little town. → elementExamples from the Corpusbe out of your element• Anyone watching would have known immediately that he was out of his element.• Miller is completely out of her element in this sci-fi role.