He had no source of Spiritual Energy anymore.
He wanted to cultivate, but there was no Spiritual Energy left.
In this Spiritless Land, he could only feel the extreme loneliness and despair. His Dantian had long been depleted of Spiritual Energy, and there was nowhere to replenish it; his body couldn't produce Spiritual Energy on its own.
Unable to cultivate, he rediscovered what sleeping felt like after a long time, but the more he slept, the more muddled his mind became, the more muddled his mind became, until... when he could no longer sleep, he had completely fallen into a mental haze.
He had even somewhat forgotten why he had ended up in this small world.
It felt as though time had been paused.