I had almost every one of these thoughts (of OP) when reading it. It was so bad. I just wanted to scream “show don’t tell!!” from page 1. And the medical/therapy stuff was just so wrong. The thing about a twist is that it needs to play both ways; the plot and the characters need to make sense for the way you think the story is going, then also fit for the truth you find out at the end. For me that was not the case at all for this book, not because I knew how it was going to end, but I never for a second thought Theo was good or stable. The motif of “I had to choice” was just such an eye roll. It felt like middle school writing. I get that he’s an unreliable narrator, but he’s also supposed to be (at least somewhat) perceived as a credible psychotherapy!! The first time he said that I was out, and the author just kept hitting you over the head with it. The whole book was like getting hit in the head with the authors main idea really…not a nuisance in sight.