What are the symptoms and treatments for thanatophobia

Thanatophobia is a fear of dying beyond what concerns most people about life ending. Some techniques that help with any type of phobia include:
Breathing techniques. Deep breathing can counter physical and mental tension. One simple method to foster deep breathing is to breathe in slowly and count to five before exhaling to another count of five. Another technique is to place one hand beneath the belly button and breathe so that the abdomen rises and falls with each breath.
Muscle relaxation. Progressive muscle relaxation (tensing and then releasing one group of muscles at a time in order to promote whole-body relaxation) can help to slow heart rate and promote calmness. 
Desensitization. This approach combines deep breathing and relaxation with gradual exposure (either through audiotapes, videotapes, or the patient’s own imagination) to the cue that most triggers the phobia..
Distraction. Putting the mind’s focus elsewhere is another way to diminish the anxiety and pain of dental visits. The more complicated the task meant to distract, the better.