If you have any type of stomach sensitivity, things like coffee, tea, chocolate are all going to irritate the stomach, its the high level of acidity. While
nexium will help with gerd, it wont do anything for
gallbladder issues.
I know you said you stopped coffee, but do you consume anything else like tea, tomato sauce, garlic, onions, spicy foods, greasy foods, fatty foods? If so, eliminate all of these things and see if the pain goes away.