Questions for Book XIX:

"the carrion blowflies
will settle into his wounds, gouged deep by the bronze,
worms will breed and seethe, defile the man's corpse --
his life's ripped out -- his flesh may rot to nothing"

The notion seems to bug Achilles, and no wonder: he has to come to grips with this side of himself. So notice the Hamlet-like obsession with the nauseating physicality of death. His mother Thetis finds him sobbing and wailing over Patroclus' corpse when she delivers the new armor made by Hephaestos. She also stuffs Patroclus' nostrils with ambrosia and nectar to preserve the corpse.
Achilles repeats a moment we've seen a couple times before in which he gets himself riled up and consciously tries to beat down his emotion: "Now, by god, I call a halt to all my anger" (19.77). Again, that's not the way it works; this is no solution to rage-aholism.
"I am not to blame!
Zeus and Fate and the Fury stalking through the night,
they are the ones who drove that savage madness in my heart,
that day in assembly when I seized Achilles' prize --
on my own authority, true, but what could I do?
A god impels all things to their fulfilment:
Ruin, eldest daughter of Zeus, she blinds us all"
(19.100-106). So Agamemnon has yet another story about the events of Book 1, with new dynamics of blame that he reiterates: "that maddening goddess, Ruin, Ruin who blinds us all ... the Ruin that blinded me from that first day" (19.151-162). Odysseus advises a very public re-alliance between Agamemnon and Achilles, and a banquet setting for it, but Achilles is too consumed with wrath. "You talk of food?
I have no taste for food -- what I really crave
is slaughter and blood and the choking groans of men!"
(19.253-255). It's still wrath; it's just to be directed elsewhere now. So he adds fasting to his list of extreme behaviors (19.249f). Most of the gifts Agamemnon promised Achilles some time ago are brought forth, with the insistence that he did not have sex with Briseis. "she flung herself on his body, gave a piercing cry
and with both hands clawing deep at her breasts,
her soft throat and lovely face, she sobbed"
(19.335-337). Briseis, presumably a female ideal here, goes into the grief melodrama when she sees Patroclus dead. Achilles is so intense that all but the key Greek captains take off. Achilles notes the absurdity of fighting over "that blood-chilling horror, Helen" (19.387). Athena sneaks some nectar and ambrosia into Achilles' system to give him the strength he'll lack from his starvation.
Finally, the arming of the horses includes Achilles' address to them and Xanthos' response.
"And Roan Beauty the horse with flashing hoofs
spoke up from under the yoke, bowing his head low
so his full mane came streaming down the yoke-pads,
down along the yoke to sweep the ground ...
The white-armed goddess Hera gave him voice:
'Yes! we will save your life -- this time too --
master, mighty Achilles! But the day of death
already hovers near, and we are not to blame
but a great god is and the strong force of fate"
(19.478-486). Achilles is a bit snippy in response, but he's now facing stage one of his final fate -- he's bound not to live long after Hector's death. So even horses blame Fate! This throws some light on how we are to take Agamemnon's cheesy excuses. Homer shows the irresponsibility of blaming Fate and mocks this inclination, since it resides even in horses.

Iliad: Book XX
Iliad Index
Orpheus: Greek Mythology