Memory foam chemicals from pillow spoiled bed and rendered it useless
I would suggest that perhaps it wasn't the pillow but another issue altogether. 

If in two days your pillow outgassed enough to saturate the wall and the plywood, a couple days should also be sufficient for those to also release any trapped gasses. As I doubt they have any properties better at trapping gases than the foam in your former pillow.

Just a couple thoughts: 

Do you have a carbon monoxide monitor in your home? A faulty furnace or water heater could be causing some of your problems.

Have you opened a window to provide better airflow?

Have you febreezed the area? The active ingredient in febreeze, cyclodextrin, does trap unwanted chemicals and gasses.

Or another chemical trap, is activated charcoal.