A man is both an animal and a spiritual being at the same time. As an animal, a man is afraid of death; as a spiritual being he does not experience death.
In the last moments before death, the soul leaves the body. It unites with the limitless, timeless, and eternal soul and transforms into another form, we know not which. After death, our body is left behind, and it becomes only an object for observation.
Death marks a change, it marks the disappearance of the dwelling place of your conscience. The conscience itself cannot be destroyed by death, in the same way as the change of a theater set cannot destroy a spectator.
Perhaps you fear the changes that death will bring? But a similar great change already happened at the time of your birth, and nothing bad came out of it.