Already it is long time that you are suffering for last 4 years,it is good you realised it.It is combination if diet and lifestyle changes that are required. Take 3 to 5 meals every day take little quantity and frequently breakfast is most important of all take regularly and light lunch and lighter dinner .
Increase water intake .Stop alcohol and smoking
.If problem is more consult a Gastroenterologist
take proper medicines for some time at least.
High fat content should be reduced,healthy fresh fruits and sprouts and salads may be increased.
Some kind of exercises are must and even yoga
helps to lead healthy lifestyle.
Strong determination is what is required
Good Luck to you