Some songs are too fucking difficult to learn

Was trying to learn 知我 and could not get the rhythms or the notes down. Finally looked up the sheet music and...fucking hell, the vocal part not only spans across two and half octaves with the highest note being a high A (barely in my range) while the lowest goes to a low G (out of my range), the measures also keep changing between 2/4, 4/4, and 6/4 mid-stanza.

My brain hurts. Also my throat is like dying.

And yes, I am trying to learn a new song to distract myself from the batshit going right now.