Caducaste comes from the verb caducar, which means 'to expire' or 'to run out', typically used for things like food or a subscription. It's an interesting and somewhat rare word to hear applied to a person's patience.
In this song, Paty Cantú powerfully uses it to say "Me caducaste la paciencia" (You expired my patience), meaning the person completely wore out her patience. It's a creative and impactful way to express being fed up.
Paty Cantu closes the door on an ex with an "Ojalá que tengas a tu lado, alguien que te quiera" (I hope you have by your side, someone who loves you) that lands more like an epitaph than a blessing. She is done pleading — "No te servirá rogarme" (Begging me won't help you) — and she is not bracing for a comeback either: "Sé que volverás, no habrá miel que me desarme" (I know you'll come back, there'll be no honey to disarm me). The sharpest line goes to whoever is next: "Pobre la que sufra tu indecencia, de tu indiferencia, de la que esté en vez de mí" (Poor whoever suffers your indecency, your indifference, the one who's instead of me) — pity for the replacement, not jealousy.