As I have a foggy brain and today included, I can tell you that I do not get chest pains. But from the discriiption you said sounds like anxiety attacks. The two don't seem to be related. Having a foggy brain causes anxiety and you just arn't think clear. So it effects your whole body and you think you are quite normal till you go outside and everyone tells you that you are not normal.
Check to see if you have hypoglcemia, even though we are on no Sugar diet, if you have a problem you might need an occasional help. This diet is not for everyone and if you are passing out there is a problem for sure. I have occasional bouts and I make the people run and get me chocolate. I dont know why that helps me. Not any kind of Sugar just a small piece of chocolate and then I am fine.