In Hemingway's "A Clean and Well Lighted Place," who are the protagonist and antagonist?

The protagonist is the older waiter. He is the character who embodies the story's overriding theme of existential angst in the face of nothingness. He is a world weary soul who's abandoned the certainties of faith and succumbed to despair. We see this in his parody of the Lord's Prayer, where he inserts the word nada (nothing) into various places.
But how to escape from this crushing sense of despair in a bleak and seemingly Godless universe? The cafe in which he works provides a place of refuge. It is "a clean, well-lighted place" where a sense of order and stability prevails. Yet this can only be a brief respite, and no more. At some point the older waiter will need to go home to bed, where he will be alone with this thoughts once more and also bitterly aware that he is all alone in the universe as he struggles to impose some meaning on an inherently meaningless existence. The futility of the attempt merely adds to his crushing sense of despair.
The younger waiter is the antagonist. His youthful naivety and ignorance of the ways of the world give him a radically different perspective from that of his older work colleague. He doesn't openly acknowledge the fundamental nothingness at the heart of life, but the valuation he puts on worldly goods shows that he is unknowingly seeking to avoid the question of his death by losing himself in endless distractions. Unlike the older waiter and the deaf old man, he has a wife. His marriage provides him with a link to the world of other selves, a world from which the other two men in the story have been almost completely cut off. In short, he appears to have something to live for. His world is indeed "clean and well-lighted."
The younger waiter cannot understand why someone as rich as the deaf old man would ever contemplate taking his own life. Nor can he begin to comprehend the cynicism and depression of the older waiter. But perhaps in the story's protagonist we can catch a glimpse of what the antagonist will become once his worldly attachments no longer constitute the "clean, well-lighted place" he thinks they do.