#hope my response doesnt sound rude anon I'm genuinely confused and falling asleep

[sneckerdoodle]

I think the question is whether Jaskier is inserting himself into the song, e.g. "I'm weak my love and I am wanting" AND talking about Geralt. Not whether the song is about Geralt and Yennefer, which it obviously is. The subtext would be how Jaskier fits into the song.

Who would the “I” be in the song if not Jaskier, though? If it’s not meant to be Jaskier, that’s so confusing because I can’t think of any other explanation. 

Maybe people are reading this as a pop song, where pov can be weird.  There’s a “her” and a “you” and an “I” in “Dog Days Are Over,” too, but idk how any of it ties together.  Who did happiness hit like a train on a track was it Florence was it the Machine?  We’ll never know.

But Jaskier is a bard and when he sings in the first person, it's from his pov as a character in the story. The speaker is bamboozled by love and accepting his penance, which fits Jaskier’s side of things. Who else could it be?