I have recently written a piece about the film Pretty Dead (see my review) for my upcoming Zombies and Sexuality collection. The film tells the story of a medical student who may be turning into a zombie, or may be suffering from Cotard's Delusion (a schizoaffective disorder characterized by the patient's belief that they have died).
In her article ‘Perdition Days: On Experiencing Psychosis’ (published at The Toast), Esmé Weijun Wang recounts her experiences of Cotard's Delusion. For anyone interested in this area of selfhood or mental health more generally, it is highly recommended reading. The first-person perspective is highly evocative.