Judah is describing to Joseph a realistic but hypothetical case of what he will expect will happen to Jacob when he returns without Benjamin. (See: [[rc://en/ta/man/translate/figs-hypo]])
To "bring down ... to Sheol" is way of saying they will cause him to die and go to Sheol. He uses the word "down" because it was commonly believed Sheol is somewhere underground. Alternate translation: "And we will have caused our old father to die of sorrow" (See: [[rc://en/ta/man/translate/figs-idiom]])
Judah refers to himself and his brothers as "your servants." This is a formal way of speaking to someone with greater authority. Alternate translation: "And we, your servants" or "And we" (See: [[rc://en/ta/man/translate/figs-123person]])
Here "gray hair" stands for Jacob and emphasizes his old age. Alternate translation: "our old father" (See: [[rc://en/ta/man/translate/figs-synecdoche]])