Knights of the Contemporary Crusade

A man wakes up. He immediately begins to curse himself and display immense self loathing. It becomes clear he is experiencing a hangover, and he attempts to regain control over his body. This self-loathing follows him into the next chapter, in which he experiences vague glimpses of his (believed to be extinguished) humanity. The protagonist discusses his predicament quite heavily, until he is interrupted with the doorbell, which awakens a hatred inside him. The doorbell is answered, although begrudgingly, and a small man is waiting and requests a moment of the protagonists time, to which  he is met with a wicked repudiation, before humanity once again takes hold of him, and he promptly apologises and allows the visitor inside. The conversation resumes inside, but it is at this point, with a fellow person as a frame of reference perhaps, the main character exudes a worrying lack of control, and especially a distinct, tenuous grasp of normal human conventions. The conversation regresses entirely into something surreal. Finally, the protagonist seems to relinquish all semblance of morality, and indeed anything resembling  sanity. The strange journey is then wrapped up in an ending tantamount to total insanity.