"Quassù" colloqual usage

I came across this phrase in CM: “Sono quassù con lui”. It’s translated to “I’m up to here with him”. This, to me is striking because it seems like a literal, word for word translation of a colloquial concept in english. “I’m up to here with him” really means “I’m fed up with him”, equivalent to the term “stufato”. “Quassù” is a literal term means “up here”, for example: “È solo che non capisco che fai quassù.”

This strike me as a mistranslation. Perhaps the italian speaker read this sentence and didn’t quite grasp the english colloquialism “to be up to here with someone” and instead thought this was a literal phrase.

Is “Quassù” really used this way? Is “Quassù” equivalent to both the direction “up here” and the colloquialism “had it up to here?”

Is this used more often than “fin qui”? I have heard “fin qui” used in this way before, but not “Quassù”.



Should be up here, not up to here.