My father is 63 years old and has less physical activity after retirement. He is suffering from severe acidity after every meal he has. He never eats oily food. He does not want to get out of home. He feels bitter taste in his mouth. He does not want to eat anything. He tried all kind of antacids but nothing works. He has been diagnosed with antral gastritis in 2018. He recovered from that. He is diabetic but his blood sugar level is normal. What is it? Why his acidity is not getting cured? Please help. Is this something serious? His sodium level is 138.