After Morning Meal Usually Hot Oatmeal Without Milk And Cup

after morning meal usually hot oatmeal without milk and cup of decaf coffee with two pieces of toast i feel shaky and nervous, cold and after bowl movement it gets better. today after a meal i had the taste of bitter acid in my mouth, nauseas and had 3 loose bowel movements,no diarrhia. i took loperimide, drank a lot of water. my question is this my stomach acting up or is it liver related. my gallbladder was removed. i have chronic gastritis. i am 74 year old woman