Good work that was a very interesting story :) I thought the main characters descent into madness was way too quick though! xD
There is a old game called Harvester which does a similar thing where is turns you into a monster but it does it in a more slow and deceitful manner. It's quite interesting you should take a look!
Just two points I noticed where the grammar needs to be fixed;
- "It's a good man" should be something like "They are a good man". In general/old fashion referring to someone as "it" can be considered quite rude and I don't think the main character wants to be rude about the neighbor.
- When you and the neighbor start talking at night you said "Good night" at the start of the conversation. It should be "Good evening" when you start a conversation in the evening/night but when your saying goodbye in the evening/night "Good night" is perfectly fine then!
Anyway really good work :)