Brit, if you get these same symptoms when your eating anything that contain wheat, rye, barley or oats, have yourself checked out for celiac disease. Alternatively, take yourself off of anything contraining those components and see if you feel better.
Did this start immediately after eating.....or an hour or so later?
I will have a hypoglycemic attack.....with those symptoms (except the rash).....about 1 hour after eating a bowl of cereal......100% of the time.
Then I need to eat protein and a carbohydrate to make it pass....I actually have glucose tablets that resolve this also.
If this is what is going on......drink some orange juice.....or peanut butter and a cracker....and lots of water......this should help
If it is an allergy of some kind....then I don't really know......
Maggie