well it sounds a little like a gluten problem, but it shouldn't come on so quickly.
This was my thought.
I would start with your primary care doctor to have them run blood test or just go straight to a gastro docor so they can figure out what's causing the problems.
I will say as caution to make sure you get a proper diagnoses. My primary care doctor tried to say my fatigue was due to depression (it was not) and my anemia was due to being female (it was not). I always had high iron in the past and didn't like her responses or the fact that it didn't change after a year or taking iron pills so I found a really good gastroenterologist who figured out fairly quickly that it was celiac.