I spend a week in Spain and since I got back to the USA, (10 days now )I have pain on my upper stomach, nauseas and headaches. I have also been very tired, dizzy and weak. This only happens sometimes (about 75 %) especially after I eat. I have stop eating because when I do, I get very sick. I went to the emergency room and they didn't find anything wrong but the doctor prescribed me Zantax. I still feel sick. I have scheduled an appoinment with a specialist but it is a week from now. Any suggestions?