Instead of omeprazole
go for Rabeprazole
Avoid spicy foods,outside foods.
Eat plenty of fresh fruits and green leafy vegetables.
Stop smoking and alchohol if you are taking them.
Please get an upper GI endoscopy
.A small cancerous lesion if at all present will be seen by this procedure.Get this test done and be relieved.
Hope it will come normal.
Nothing to worry
Wish you good health