An inflamed organ
The sudden pain in your upper abdomen was so piercing that it caused you to double over. It radiated from your upper abdomen directly to your back. Lying flat made the pain worse. Curling up into a ball helped only a little. Your breathing was shallow because taking deep breaths caused even more pain.
Your doctor said your symptoms were typical of acute inflammation of the pancreas (pancreatitis). An attack of acute pancreatitis is often sudden, severe and steady. Mild cases generally improve within a week. Moderate to severe cases may require hospitalization and take longer to improve.