How can I fix this thesis i made on the imagery Frederick Doul uses in his book?

In the story The Narrative of the life of Frederick Dougl, the author Frederick Dougl uses multitudes of different illustrations to show the inhumane treatment of the slaves. Dougl includes great amount of details to emphasize the horrific cruelty black slaves experienced. Many of these situations involved blood and gore throughout the page. The The Narrative of the life of Frederick Dougl is a powerful compilation of writings that’s proves the sickness of the men during this time period.