caledonia , i'm experiencing exactly the same thing and it started 4 weeks ago.
It's getting worse and worse and last week i had to go to the ER because i thought i was losing my mind and my heart was racing. I got some xanax and have been using it since then.
For me it's purely physiological and not psychological, it happens right after eating or sometimes even during eating when i'm consuming a larger meal.
I've been experimenting with macronutrient ratios the last few days but have not found out what's causing it yet, although i've noticed a meal high in fat and / or protein causes a more severe anxiety / panic effect than a carb meal.
I have about 50+ severe IgG scores but i've been avoiding those for a while now. I believe it's some kind of immune reaction OR a liver-related problem. My guts are inflamed at the moment and my food isn't getting digested!
Do you have any GI disturbances or problems liver/spleen/pancreas?
I'd really like to hear from you if you have found out what's causing it because it's freaking me out!