None of this is real.

The protagonist wakes up in a suburban home to find they apparently have a wife, a child, and a dog, none of which they have memory of. As the so called family members reference warm familial memories they cannot recall, complete with photos of their vacation trips, the protagonist starts accepting that they might have amnesia or had an aneurysm... until they find a piece of paper in their pocket saying 'none of this is real'. Reality itself starts glitching in increasingly bizarre ways.