What internal conflict is making the narrator nervous in The Tell-Tale Heart?

The Narrator is a Paranoid Schizophrenic, but back in his time period, almost nobody knew or could identify what that was. Schizophrenics often see things or hear voices in their head that "persuade" them to do things, and occasionally are set off by a specific object. In this man's case, it was the old man's eye. Paranoid schizo's are actually known to have sharpened hearing, which was why the Narrator talked about his "sharpened senses". Throughout the story, he went over the fact that he wasn't a madman, but the assurances were more for himself than the reader. He went over every detail of the killing, assuring the reader that he wasn't crazy, when really, his "normal side" was the person that he was trying to persuade. When the police show up, he seems to be almost spectating the interrogation, and finds it amusing. Then the paranoia kicks in, and he thinks he sees the Eye, then the heartbeat, and believes the policemen are just toying with him. He finally snaps and shows them the body, feeling a great sense of relief. In short, the narrator was at war with both sides of his personalities, and his schizophrenia eventually ate him up.