This may not be the very best site for the information you are seeking, but the answer to your question is not that technical. I wish there was good news for you, but I'm afraid there isn't. Your drywall is ruined and is the source of the odor. Drywall is nothing more than plaster sandwiched between layers of paper. The paint protected the outer surface so it appeared to have no damage, but inside the walls there is no such protection. Sadly, once the plaster is soaked, it is ruined. You must rip out all of the drywall that was exposed to the water to prevent mold. The wood framing should dry OK once the drywall is removed. You didn't mention anything about your water heater, but if by chance you have a gas heater, if it got flooded, it is ruined. It can not be repaired, so do not even attempt to use it. We had lots questions about this after Katrina in NOLA.