Perhaps this is something that comes with old(er) age? If I am lucky I might have another 20 years, or I could die tomorrow. The only thing certain in life is that we all die, some far too soon. The great religions of the world all speak of some kind of life after death. The truth is we just do not know. Some with great faith believe they have the answers. I prefer to accept my doubts.
I do not remember anything before I was born, so eternal "nothingness" is possible. I guess all humans hate to think in terms of finality. The best ones are those who can accept life as a gift and to live their lives fully. Some argue that without a life after death we have no real moral compass.
In the end I am agnostic - what will be will be. All the major religions seem to strive to understand the ultimate question. One day we will all know the answer.