When expressing the sentiment "it's you that I need," it can be helpful to have some synonyms on hand to mix up your language and express your feelings in different ways. Some alternatives to consider might include "you're the one I want," "I can't live without you," "you complete me," "you're my missing piece," "I need you in my life," "I'm nothing without you," "without you, I'm lost," "you're my soulmate," "you're the love of my life," or "my heart beats for you." Each of these phrases carries a slightly different emotional weight and can be used in different contexts depending on the situation and the depth of the relationship.