Derroche means 'waste' or 'squander'. It's a strong verb that implies an excessive or careless use of something valuable, often with negative consequences.
In the context of this song, the singer uses derroche to express that they never wasted or squandered their love and effort on the person who caused them pain. They are asserting that their devotion was genuine and not given lightly, making the other person's betrayal even more impactful.
Pavel Núñez's "Sufre Más" is a powerful song about getting even after a painful breakup. The singer wants their ex to experience the same suffering they went through. They sing, "yo nada más como yo sufrí por tu desde él y así verás lo que llore por ti sufre más" [just as I suffered because of you and him, and so you will see what I cried for you, suffer more].
It's a blunt message, with the singer wanting their ex to truly understand what it's like to have a great love thrown away. They gave their all, "me entregué mi ser con sinceridad con ardor" [I gave my being with sincerity, with ardor], but the ex made them believe they were the problem. Now, the singer wants them to "comprenderás lo que es tener un gran amor sin bella como yo" [understand what it is to have a great love without beauty like me]. It's a cathartic anthem for anyone who's ever felt wronged in love and wished for a little poetic justice.