Traduction - Hébreu-Anglais - אנחנו מאבדים הכל,

I think that חוץ ממה would be better translated "except of" what we ... instead of "but" what we ...

I think you're right (though it would be 'except for', not 'of') if it was someone just speaking normally, but this is sort of a 'saying' of some sort, so I felt it needed a more formal sound to it, and 'except for' just didn't cut it.