I am sorry to hear about your recurrent and persisting medical problems. It is difficult to diagnose this on net, but I’ll try and explain in detail what you can do to reach a diagnosis.
First of all, since you were in Thailand, and since it all started with vomiting and diarrhea, it is important to get a stool test to rule out parasitic infestations, especially amoebiasis, giardiasis, tape worm, round worm, etc. All these can cause malabsorption, anemia, weight loss etc. The anemia and weakness can cause the heart to beat faster. So, along with stool test you need to test for anemia, low vitamin B12, and electrolyte imbalance.
Other than this, you do appear to suffer from acidity and gastric reflux. You also need to find out if you have H pylori infection. Many a times a persisting H pylori infection can be the cause behind acidity not responding to treatment. You will need to take a combination of medications (under medical supervision) like a proton pump inhibitor such as omeprazole, lansoprazole or pantoprazole empty stomach in the morning and an antacid gel after meals or H-2 blocker such as ranitidine for complete relief.
Also you need to make some life style changes such as taking a late night snack, drinking cold milk, avoiding heavy meals and eating frequent small meals, avoiding too much of caffeine, tea, smoking, fried food and drinks both alcoholic and non alcoholic fuzzy ones, avoiding heavy exercises within 4 hours of a heavy meal, raising the head end of the bed by pillows to 30 degrees, and avoiding lying down for least 2 hours after food.
A comprehensive investigation is required keeping all the points in mind. Please consult your doctor regarding this. You may also need to consult a GI doctor.
Hope you get well soon! Good Luck and take care!
Ok, I will try to see the doctor and get tested for these things, I guess I need to be sure that way I know what I can eat.
Thank you for taking the time to help, really appreciate it.