This might sound a bit crazy given what you said, but have you tried light exercise straight after your daytime meal? I too get completely incapacitated by foo

This might sound a bit crazy given what you said, but have you tried light exercise straight after your daytime meal? I too get completely incapacitated by food, my heart rate goes up, and i usually just lie down (haven't measured my blood pressure), but if I go to the gym and do light aerobic exercise for 45 minutes (keeping my heart rate around 135-145) then the worst of the symptoms are abated. Also, the brain fog doesn't matter if you're on a treadmill, it's actually quite a good thing to zone out. Most importantly it allows you to be productive during that time, and later on when you are back to normal you have more time to do other things as you have already gotten your exercise out of the way.