Trastornado means 'disturbed,' 'unsettled,' or even 'deranged.' It's a powerful adjective that goes beyond just being sad.
In this song, Bad Bunny sings, "Desde que te fuiste sigo trastornado" (Since you left, I'm still disturbed). He uses this intense word to express how the breakup has deeply affected his mental state, leaving him feeling completely messed up and unable to move on. It's a very raw and emotional way to describe heartbreak.
Ever find yourself wondering what an ex is up to? That's exactly where Bad Bunny is in this song. He's asking himself, "¿Qué hubiera pasado / Si estuviésemos juntos, aún enamorados?" [What would have happened / If we were still together, still in love?]. He's stuck on the details, wondering if she's kissing someone new or if her eyes have already forgotten him. It's a slow, sad reggaeton track for anyone who's ever looked back and thought about a different path.
He gets really specific with his memories, which makes the song feel so personal. He admits he still has a photo of them dancing when they were underage and that he misses her on Valentine's Day and Christmas. He even recalls intimate moments in the back of a car. He insists that even though he's tried to move on, "A otra persona no he podido amar" [I haven't been able to love another person]. Since she left, he says he's been "trastornado" [disturbed or unsettled], just thinking about what could have been.