Is there a best way to get over fear of terrible death?

Thanatophobia ?: Extreme/ irrational fear of dying? Consider cognitive behavioral therapy to work through it.

Classical Homeopathy: You first need a full evaluation of your fears, which may not be the only issues you're experiencing. Extreme fears of death are possible in many conditions, including phobias, ptsd, other anxiety disorders, depression, and even some psychotic illnesses. If appropriate though, classical homeopathy with an experienced homeopath can be extremely helpful -- along with skillfully done cbt.