Dealing with the Fear of Losing a Loved One

Had a great time trick or treating with my kids and visiting my parents who are near by. Next year we move the next state over. Not very far but I have always lived close by to my mom. Our relationship has not always be great but she is my mom. She is 70 and I am just laying here seeing how the years are flying by and then bam death comes to mind. I can barley keep it together to move and then the thought of not even being able to call her is so upsetting:0( it then triggers me to think of how one day I won’t be around for my kids and it is even more upsetting. I death is and can be a scary thought for many but has anyone else out there had these thoughts plague them? If so how have you eased the fear?