Fear of death can be crippling for some people. If you haven't done so already, you may want to see a psychotherapist to better understand its basis in your particular situation and to help you with strategies for managing this severe anxiety. May I suggest also reading "Staring at the Sun," the book by the psychiatrist Irvin Yalom quoted in this post. He is a far more skilled therapist and writer than me. For some background and context about Yalom, look for an Oct 2017 article in The Atlantic titled "How to Die."