Amethyst and his fear

This story take place between 3010 to 3026. Amethyst starts out a 16 year old boy who ends up in this spider infested world. Amethyst must learn to fight and kill spiders of varying sizes, some smaller than him while others are much bigger. In order to get back home he must defeat the king spider, a 15 foot tall spider. Will Amethyst survive the battle and get back home to his family and friends?

Prompt: "Center your story around a character whose biggest fear or worst nightmare comes true"