How do I look emotionally connected to a song when I don't fully understand the slang?

I’m preparing a vocal cover of a beautiful Korean R&B track. I translated the lyrics, so I know the general meaning is about a breakup.

But when I watch myself sing it, my facial expressions look so flat or fake. It feels like I’m just pronouncing words rather than telling a story. 📉 For those who aren't fluent in Korean yet, how do u tap into the emotional nuance of the language? Do u connect the lyrics to personal memories, or is there a specific technique to make the diction sound more emotional?