I have had a headache off and on over several days, I thought it was more of a tension headache but this morning after coming up a flight of stairs from basement I was a little short of breath and then felt jittery. This was only an hour after eating breakfast. I ate a banana and graham crackers and drank 2-3 cups of water and felt better. But I also had two loose stools and thought it could be from Chinese food I had eaten Saturday night and leftovers for lunch Sunday. Then later in morning I stopped at two stores but on way home I had a sudden onset of lightheadedness while driving and became quite alarmed, I had air conditioning on and turned it up, finished a bottle of water I had in van even thought it was warm and did several, slow, deep breaths which helped within a couple minutes, maybe less. I was afraid I was going to pass out or worse while driving and know I should have pulled over but I did talk myself down. I have just felt off today, still headachy and even some slight nausea. Any ideas?? Thank you