The delusion of constantly thinking you're going to die very soon is known as "death anxiety" or "death delusion." It is a type of delusional belief where an individual is convinced that their death is imminent, despite any evidence or medical indications to the contrary.
Death anxiety is associated with various mental health conditions, such as anxiety disorders, depression, and psychotic disorders like schizophrenia. In some cases, individuals may also experience this type of delusion as part of a broader medical condition or during high-stress situations.
It's crucial for individuals experiencing such beliefs to seek professional help from mental health experts or medical professionals. Treatment options may include therapy, medication, and supportive care to address the underlying condition and alleviate the distress caused by the delusion.