Death anxiety as an Atheist

This been posted a bunch of times already but not all advice line up well, is it possible to graps the idea of eternal nothingness and ceasing to exist or will this always be a dilemma, yes i remember nothing before birth nor the 14 billion years prior but still, the thought haunts me that my chronic illness battle will be worthless. Amy ideas how to grasp the concept of existence as a very atheist man.