Until I Met Her

The shifting viewpoints added layers to the mystery, but I wonder if this was planned from the start or developed during writing. How did it influence the story's tension?

The psychological unraveling was intense, and I kept questioning what was real. Did others find it hard to trust what they were reading at times?

There were moments when I felt I knew too much, then suddenly everything shifted. I'm curious about the techniques used to keep the reader hooked.