Sediento literally translates to "thirsty." While it's a common word, its metaphorical use in this song makes it particularly interesting and evocative.
Nicky Jam uses it to describe love itself: "Vamos a salvar a nuestro amor sediento" (Let's save our thirsty love). This personification of love as something parched and in need of sustenance creates a powerful image of a relationship that is fading and desperately needs to be revived. It's a unique way to express the longing and effort required to rekindle a lost connection.
The breakup in "Comenzar de Nuevo" has already happened quietly, before the first line. Nicky Jam opens on the symptoms instead of the fight: "Tú, el frío en las palabras" ("You, the chill in your words"), then "Viendo las horas pasar en silencio" ("Watching the hours drift by in silence"). What he asks for is oddly specific. Not forgiveness, but a second run at the same courtship with the damage left out: "volver atrás y comenzar de nuevo" ("go back and start over") and "Y conquistarte como sé que puedo" ("and win you over like I know I can"). The best line in the song is the one he picks for wanting her, "yo te deseo como vela al viento" ("I want you the way a sail wants the wind"), which is a sail admitting it does nothing on its own.
Then the apology turns into a sales pitch, and that turn is what makes the song fun rather than sad. By the last verse he is arguing his own case: "Tú sabes bien que solo yo sé cómo hacerte enloquecer" ("You know perfectly well that only I know how to drive you crazy"). The track agrees and stops grieving on the spot. He calls out to his producer, "Dímelo, Kike, rompimos con esta" ("Tell me, Kike, we killed it with this one"), promises Puerto Rico "A una rumba de verdad" ("A real party"), and hands the rest of the song over to la-la-la.