Came upon your question by accident as I do not post around here...
"* Symptoms usually subside during meals. Meals do not appear to mask them but genuinely reduce stomach cramping, nausea and even the degree of mental fog, yet 20-40 minutes after meal the symptoms return with vengeance and generally are much stronger then before the meal.
That tells me you have an infection, which may very well be something in your stomach. When you eat, your immune system is stronger, but very soon after that the infectious agent eats what you ate as well, and the infection gets worse.
Try eating low glycemic index foods to see the difference. Good meat and green vegetables.
I have an idea of what it could be, but what is puzzling is - how did it start so suddenly?
It would be great to hear more about what you were doing in the weeks just prior to start of your symptoms? Any trips, new acquantances, parties, unprotected sex, making out, going to nature (camping), medical interventions including dentis visits, and so on?