Entregar literally means "to deliver" or "to hand over." However, in the context of emotions and relationships, it often takes on a deeper meaning of "to surrender" or "to give up" oneself completely.
In "Sin Tu Amor," the singer uses entregar de nuevo el corazón (to surrender my heart again) to express the vulnerability and hope of falling in love after experiencing pain. It's a powerful word that captures the emotional depth of the song.
"Sin Tu Amor" is built entirely around one sentence: "No hay mas palabras que decir" [there are no more words to say]. Everything he adds after that first line is proof he's still trying to find some anyway. Every chorus lands on the same four words, "Yo sin tu amor" [I without your love], repeated until they stop sounding like a description and start sounding like an argument he's having with himself.
The verses tell the real story: twice he gets as far as "Estaba a punto de ir a buscarte" [I was about to go find you] and stops both times. That's the actual subject here, not the breakup itself, but the specific, repeated moment of almost going back and choosing not to.