Based on my reading of the story, this sentence means that the protagonist has accepted his fate. In this quote, “Gazing up into the darkness I saw myself as a creature driven and derided by vanity [...]” I feel this is where the protagonist has seen what is true about himself and in this moment he is accepting the reality. However, just because we accept something, does not mean that we have to enjoy it. Which I would say is what the protagonist was trying to communicate to us, the readers, in this line: “[...] and my eyes burned with anguish and anger.” The ‘anguish’ and ‘anger’ that the protagonist feels is because of this new found reality he has “awoken” to. He is finally able to accept the true nature of himself, and he’s discovered that it is quite different from his original understanding. In my personal opinion, this sentence from the excerpt reveals that the protagonist has finally become self-aware.
the narrator finally faces the darkness he has been trying to escape, and the reality of his situation causes him great anguish and anger. I hope it helps!
