Hi. My Upper Left Stomach Is Buzzing, Or Vibrating. I

Hi. My upper left stomach is buzzing, or vibrating. I have nausea and pain sometimes too along with it. I have celiacs disease. I take dexilant for gerd. I am doing great on my diet. I did recently start an aerobics program two days ago. I feel so awful I can't do it anymore. I had my heart checked about 4 months ago because I had extremely high cholesterol. ( EKG, Nuclear stress test,both neck veins ) Everything was great. My cholesterol was checked a year and a half ago. It has gone way down. The heart test was done to see if I was fit for exercise.