This statement expresses the profound importance and reliance the speaker places on someone in their life. It suggests that the person is not just a want but a necessity for the speaker's well-being and survival in the world.
The phrase "You are everything I need to survive in this world" conveys a deep emotional dependency, emphasizing that the person is crucial for the speaker's emotional, mental, and perhaps even physical well-being.
Overall, this statement reflects the deep bond and reliance the speaker has on the person, highlighting their significance as a source of support, comfort, and emotional sustenance in navigating the challenges of the world.