Who remained when everyone was killed

Today it cracked me open — the thought that everyone I knew has died. I have lost everyone. Passing through points of reset to zero, I lost even those who lived a month, a week, or a day. No one remained. Emptiness in a vacuum. But who is HE that watches all this? Why does HE not vanish into this vacuum? Why does HE live and see only death? Why does he watch everyone dying, yet himself stays alive?

Does HE live because he is already dead himself? If he is dead, why does he carry the weight of all those who already died? If he did not die when everyone died — was he never born? Is HE immortal? Who is this HE?