If you are having abdominal pain since 4 years ,why you have not got examined by the gastroenterologist?
Your symptoms esp pain in empty stomach may be related to gastritis ,peptic ulcer
The medicine which are using contains painkillers which are harmful to your stomach.
Next Steps
see the gastroenterologist ,may ask you for hpylori antigen test to rule out Hpylori infection in your stomach or he may ask for upper gastrointestinal endoscopy depending on your examination
Health Tips
avoid non steroidal anti-inflammatory pain killer like Zulu
avoid spicy food and smoking