1. I adore your hat, Tinkerbelle (I'm totally a hat person having been bald--not by choice)(my hair incidentally just magically grew back--okay, I made a lot of changes that quite likely encouraged the spontaneous regrowth of HAIR! I still hide under hats, bandanas, etc. just because I feel safer, i.e. less anxious and more me)
2. How varied is your diet? Do you rotate what you eat?
3. Could you be sensitive to something that you've been consuming on a daily basis? Egg whites? Avocado? Something in the bread? A preservative? I don't know, I'm probably way off base.
4. I go through phases like you, too. What I do basically is eat mostly really plain rice/sf. Lots of organic no-chicken broth--for the SODIUM. Keep Immodium handy and gastrolyte/pedialyte. Keep your electrolytes in balance.
5. This is really a mystery. Sometimes there is no known explaination.