Nietzsche and der letzte Mensch

There has always beena contradiction in Nietzsche as he propounds both the notion of The Last Man (der letzte Mensch) and the doctrine of Eternal Recurrence in Also Sprach Zarathustra. How can he discuss the last of anything in a framework where every action, every combination of matter, must reoccur for all eternity? It is a temporary "last"? Doesn't the end of something become hollow when that end is endless? Is this the abyss?

But then, he did call the horror of the Eternal Return das schwerste Gewicht: "the heaviest weight imaginable." Maybe the true Last Man lifts that weight.

Is the Ouroboros eating itself eternally, or is it continuously vomiting itself into being?