Can Ibuprofen and Omeprazole treat gastritis?

Hi doctor,

I am asking questions on behalf of my mum. She is having some symptoms that appear commonly with gastritis or peptic ulcers. She is 57 years old and was diagnosed with rheumatoid arthritis, hypertension, and Sjogren's syndrome in the past. She weighs 174lbs. She has a list of symptoms. She has nausea, vomiting, loss of appetite, weight loss in the last five months. She has a twisting sensation in the stomach causing pain. She has indigestion, acid reflux, dizzy spells, fainting spells, chronic cough, and back pain previously in the past.

She took Ibuprofen and Acetaminophen to manage her pain caused due to arthritis in the last three years. She took prescribed medicines for arthritis and stopped it after few days. She also takes curcumin or turmeric, fish oil, CBD oil, and Boswellia serrata to manage her pain caused due to rheumatoid arthritis and Sjogren's syndrome. After a few days, she was prescribed Prochlorperazine and Omeprazole. The first one does not show any effect and the second have some little effect.

Due to her medical causes, she lived an inactive sedentary lifestyle for many years. She is advised to do gastroscopy and CT colonography soon. I have some questions. What is the treatment that helps to manage her symptoms? I am willing to have oxygen therapy administration to manage vomiting, nausea, pain, and coughing. I heard that it helps to some extent. Is it good to use oxygen therapy in the form of an oxygen concentrator device to provide relief for her symptoms?