My heart shrinks inside me. Fear of death has come over me.
Because the enemy so oppresses him, he is afraid that he may not survive this; death looks him in the face. Psalm 55:10–15 shows the threats. The opponent is shown, both as an individual and as a (large) group.
Fear of death may also overtake a believer. For example, listen to Hezekiah in Isaiah 38:9–10 about his illness After he had…recovered from his sickness: I said, In the middle of my days I must depart; I am consigned to the gates of Sheol for the rest of my years.
4 My heart is in anguish within me; the terrors of death have fallen upon me.