I am a 30-year-old male experiencing frequent acidity and digestive discomfort for the past few weeks. I often feel a burning sensation in the stomach and chest, especially after eating spicy, oily, or heavy meals. Sometimes I experience bloating, excessive gas, sour belching, and a feeling of fullness even after eating a small quantity of food. The symptoms are more noticeable at night or when lying down after meals. I occasionally feel nausea and mild stomach discomfort but have not noticed vomiting or blood in stools. Temporary relief is obtained with antacids, but the symptoms keep recurring. I would like to know the possible cause, whether this could be gastritis, acid reflux (GERD), or another digestive condition, what investigations may be required, and the most effective treatment along with dietary and lifestyle modifications to achieve long-term relief.