We have to accept death. All living things will disappear. Our world has a certain life span. The universe has a certain life span.
After a specific moment, all energy in the world will be gone. And everything will be gone without asking for it.
It will be in big crunch as it is the big bang.
Everything in our life has a deadline. And beyond our life, as well. I do not believe in the immortality. I believe in the longevity. Many animals can live for over two hundred years. Scientists say that many insects live for a thousands of years, just falling into anabiosis. In this case, I believe, that some sort of immortality might exist.
For this, biological structures of animals in the nature can be examined. For example, elephants and turtles can live for 150-200 years.
Long life exists in other living things. It may be logical to examine them and apply them to human life.