PTSD is one hell of a thing, isn't it? It can send you back to the darkest of places. A wasteland of nothingness until an image finally forms. But maybe that's what hurt you. A wasteland of nothingness. Or in Elizabeth's case, submerged underwater, the vastness of the ocean, being dragged down by something clamped onto her leg. Until her leg ripped off. And her entire world changed.