This is a love declaration sung with a hand on the heart, literally. It opens with "Poniendo la mano sobre el corazón" (putting my hand over my heart), and the singer wants to say it "al compás de un son" (to the beat of a son). A son is the Cuban musical style behind so much of this music, so she is promising to say it in her own rhythm.
What she wants to say is simple and total: "tú eres mi vida" (you are my life) and "no quiero a nadie" (I love no one else). My favourite line is the closeness of "respiro el aire que respiras tú" (I breathe the air that you breathe), love measured in shared breath. Then the chorus gets lavish: "Amor de mis amores" (love of my loves) and "Sangre de mi alma" (blood of my soul). She asks for "las flores de la esperanza" (the flowers of hope) and offers back "la dulce verdad que tienen mis dolores" (the sweet truth my sorrows hold). Notice the Spanish trick in amor de mis amores: repeating a noun this way means "the greatest of all".