It seems like you are suffering from gastritis.
Chronic gastritis is a very common cause of abdominal pain and vomiting. It causes generalized feeling of fatigue and sickness. Gastritis also explains the symptom of lump in the throat in your situation. It is clinically described as Globus sensation.
I would recommend the following-
1)Get a urea breathe test as Helicobacter pylori infection commonly co exists and causes chronic gastritis and ulceration.
2)Start taking Tab. omeprazole twice a day before meals. This is a symptomatic treatment and will require addition of antibiotic s in case of H.pylori infection. You can also use other oral antacids.
3)Follow good food habits, i.e. have timely food and do not skip any meals. Also avoid junk food as they increase the secretion of acid.
4)Drink lots of fluid and have a healthy diet.
5)Do not sleep immediately after meals as they can cause gastro esophageal reflux disease.
6)If the problems persist for too long consult a gastroenterologist who might perform a endoscopy.