Before resorting to HCL supplements which would be better answered by seeing a GI specialist because of side effects in using them, there are some simple tips that can be tried. Apple cider vinegar which can be added to a salad is highly acidic.

Reduce processed foods and change eating habits to a healthier diet. A Registered Dietitian, particularly one connected to a GI cancers department is very knowledgable and can provide menus and nutritional guidance is using less processed foods.

Drink less liquids during a meal. I remember a child being lectured by my Father to consume less liquids during the meal and save the larger amounts between meals. He never explained why but as I grew older and had courses in physiology, it started to become clear that there was a scientific basis behind what he was saying. Stomach acid plays a role in pre-digestion of protein before it moves into the intestine where the protease enzyme then completes the digestion. Drinking a large volume of liquid during the meal dilutes the stomach acid. The pancreas produces three main digestive enzymes-amylase to digest starches, lipase to digest fat and protease to finish the digestion of meat that was acted on by HCl in the stomach. Large volumes of liquids during the meal will dilute the enzymes and their activity. So it is better to limit liquids to an amount where you are comfortable in helping to swallow food and avoid the feeling of a parched throat.

If stress is an issue, try to manage it with doing about 30 minutes a day of moderate exercise such as walking.