There are numerous causes of right-sided abdominal pain, including but not limited to liver infection/inflammation (hepatitis), gallstones (cholelithiasis) or gallbladder infection/inflammation (cholecystitis), kidney stones (
nephrolithiasis) or kidney infection/inflammation (pyelonephritis), bowel infection/inflammation (enteritis, colitis, or appendicitis), hernias, or cancer. Given your poor eating habits, you may have gas and/or indigestion. This symptom checker from familydoctor.