The declaration "You are for me" signifies that the person holds a unique place in the speaker's heart. It's a way of affirming that among all the people in the world, this person is the one who matters the most.
The statement "You are my everything" carries profound sentiment. It means that the person is the center of the speaker's universe, their source of joy and fulfillment, and the most important presence in their life.
In essence, this statement beautifully conveys the depth of love and admiration the speaker feels for the person. It celebrates the idea that some individuals have the power to touch our hearts so deeply that they become the very essence of our existence, making them truly irreplaceable and cherished beyond measure.