https://thenewkokoro.com/2020/09/15/milk-cannot-heal-ulcers/

A peptic ulcer is an open sore in the lining of either the stomach or the duodenum. Duodenum is the first part of the small intestine. Ulcers are usually painful, especially when the stomach is empty.

It appears no specific foods aids the healing of ulcers. Ulcer healing takes time and medication.

Some people have assumed that milk can help in healing some kind of ulcers in the stomach. That is not true. Milk may help for a while but it fundamentally stimulates the production of hydrochloric acid in the stomach. Hydrochloric acid in the stomach may make the ulcer to hurt more and increase in intensity. This does not suggest that you should avoid milk consumption. Take it moderately.
Avoiding or reducing intake of some foods helps to soothe the effects of the ulcer. Such foods include cola, coffee, tea, fruit juices, alcohol, chocolate, garlic, chili, black pepper, etcetera.

Bloating, belching, heartburn, vomiting and weight loss are what one observes when one has an ulcer. Black stools may be produced when a person has a bad ulcer that bleeds.
Ulcers are not caused by stress. What causes ulcer more is an imbalance of gastric juices referred to as pepsin. This is caused when Helicobacter pylori (H pylori) infects the stomach.

Using non-steroidal anti-inflammatory drugs for a long period may also cause an ulcer. Such drugs include aspirin, ibuprofen, etcetera. A number of prescription non-steroidal anti-inflammatory drugs might cause ulcers too.
Symptoms of ulcer are pain or burning sensation in the middle of the abdomen. The pain may become more intense when the stomach is empty, weight loss, loss of appetite due to pain, dull or sharp pain in the stomach, acid reflux or burping, heartburn, pain that gets away after eating, dark tarry stools, anaemia, bloody vomits.

In summary, consult your physician for appropriate tests and medications if you feel ulcer symptoms.