The poem
If your Nerve, deny you -- Go above your Nerve -- He can lean against the Grave, If he fear to swerve --
That's a steady posture -- Never any bend Held of those Brass arms -- Best Giant made --
If your Soul seesaw -- Lift the Flesh door -- The Poltroon wants Oxygen -- Nothing more --
With a little help from the dictionary for "poltroon" (a cowardly person), the poem takes flight. Emily's advice is to lean into the grave and open one's throat. If we are lucky, we may have someone (like ED) we can take a breath with when we lose our nerve.
Shant you'll have more to tally than to cry upon a nigh. Let be know a time has arised where heart is the only savior. It is passion that will one day ruler, let us hope.
Do not worry. Death is a solid relief.