I often feel these odd shudders in my stomache. my stomach kind of shakes. it freaks me out. what could it be?

Could be diet,wt.,,,: This could be due to diet from foods that cause reflux esophagitis like orange juice, tomato sauce, and chocolate, and others that result in acid production by the stomach. Alcohol can do some also. Being overweight also may have a part in this as can ibuprofen. It might be a good idea to see your doctor for an exam and to discuss diet modification. Good luck.