In phenomenological philosophy (centrally, Edmund Husserl), "all consciousness is consciousness of something." If death takes away what you are conscious of, which is arguably the world, then in some sense your consciousness would be at the very least empty. (Such an experience seems unimaginable, as unknowable as the other unknowable things you talk about.) I think it could be that empty consciousness is what life after death is, and it could be a more peaceful existence than life (it could be heaven in some sense). Confronted existentially with the unknowable, I can't think of what else to do but try to live a good life.