In my opinion it is not death that is frightening, rather what we would left undone that brings anxiety. I have met many people who are satisfied of their lives to the point that they no longer fear death. The Egyptian novilist Naguib Mahfouz once said “ Fear doesn’t prevent death. It prevents life”.
When your mind percieves your life as a story or a continious and linear progression of events, death would mean the end. But as we percieve life as only the current moment the fear of death would gradually fade away.