I am one who is completely at peace with my belief that there is no continuance of my life after my cells stop metabolizing. What is so difficult for many to entertain (that there is no continuation of one's life or consciousness) is easy for me to accept.
I don't believe any of our lives matter at the cosmic scale. I don't believe there is any god/cosmos defined purpose for anything. I believe it is possible, as some Buddhists have done by overcoming attachment, to continue to live without a sense of purpose. But, many of us need meaning and purpose. I matter to my wife and child(ren). My life has meaning to those I live and work with. I have given my life purpose to help others in their lives. So, although my life may not matter at the cosmic scale, it does matter locally in space and time, and that is enough for me. I don't need or desire my life and influence to extend farther than that, infinitely in space or into eternally in time.