English Translation
This week was the last straw.
This week was the last straw (?) Looks more like, This week he/she/it broke the glass. to me.
This week was the last straw.
This week was the last straw (?) Looks more like, This week he/she/it broke the glass. to me.
If the spanish is the original sentence, i feel we are missing a truckload of context to make an accurate translation. The sentence doesn’t make much sense as a standalone. So going for a literal translation seems the only choice. And, in that, your suggestion is better than the one we have.
If the original was in english, maybe a equivalent idiom would be useful; I’d go for: “esta semana fue la (gota que) colmó el vaso”