Literary writing, academic writing, and colloquial internet writing are all pretty different. Native speakers often struggle with literary and academic/nonfiction reading too. It might be helpful to start with shorter and simpler texts, and to listen to the audiobook version while you read it. For novels, you could also try reading middle-grade and young adult books. The writing in them is more straight forward and could help ease you into reading more complex books.

Practice. Keep at it. Have your translator app handy.