The speaker describes reading as a kind of dropping out of the world: stepping into "a hole in the middle of a book." The book itself feels hostile. It "grew like violence / on the tongue," as if its words are something harsh you can taste and can't easily swallow. The title tells us it's a depressing novel, and the poem lets us feel that heaviness rather than explaining it.
In the second stanza, the book's noisy, harsh language ("a discourse of din") and its "hard cold days" leave the speaker with a bleak idea: that we only really live "once or twice in a life." That line is the sharpest turn. It suggests that most of existence passes without feeling truly alive, and the book has convinced the speaker of it, or at least made it seem true. The mood is bleak, numb and a little claustrophobic, like being pulled into a story that quietly rearranges how you see your own life.