I believe that the song was suppose to be about a girl who wanted this guy so bad, that she pretended to be "his type" so he would like her. She wasn't planning on actually falling in love with him, and vice versa. Now she knows that they were in way too deep and she has to come clean and break up with him, because she knew that she was decieving him the whole time, and living a lie. She felt lost in his arms because he wasn't hugging her, he was hugging the person she pretended to be.
I believe that the song was suppose to be about a girl who wanted this guy so bad, that she pretended to be "his type" so he would like her. She wasn't planning on actually falling in love with him, and vice versa. Now she knows that they were in way too deep and she has to come clean and break up with him, because she knew that she was decieving him the whole time, and living a lie. She felt lost in his arms because he wasn't hugging her, he was hugging the person she pretended to be.