Severe abdominal pain triggered by walking or working is a serious symptom that requires immediate medical evaluation rather than self-medication. Pain on exertion could indicate conditions like an abdominal wall hernia, pelvic issues, appendicitis, or even referred cardiovascular pain. Taking painkillers without a diagnosis can mask important symptoms and delay crucial treatment. Please do not take any pain medication at this stage. I strongly recommend visiting a doctor or going to an emergency room immediately for a proper physical examination and diagnosis to safely determine the exact cause of your pain.