Acute Pancreatitis: Given the history of large alcohol consumption the previous day and severe epigastric cramping, acute pancreatitis is a strong consideration. The pain is consistent with this diagnosis, although the lack of radiation to the back is not typical. However, the recent alcohol use and the severity of the pain make this a leading candidate.

Gastroenteritis: Although the patient mentions no nausea or vomiting (NVD), gastroenteritis could still be a cause of severe epigastric cramping, especially if the patient has been consuming foods or drinks that could irritate the stomach.
Peptic Ulcer Disease: The use of GLP-1 agonists can increase the risk of pancreatitis but also might have gastrointestinal side effects. However, peptic ulcer disease could present with severe epigastric pain, especially if the patient has been consuming alcohol, which can irritate the stomach lining.
Food Intolerance or Irritation: Given the patient's last meal was cereal 6 hours ago, an adverse reaction to something consumed could be considered, though this seems less likely given the severity of the symptoms.

Myocardial Infarction: Although the pain is described as epigastric and not radiating to the shoulder, back, or chest, myocardial infarction can occasionally present with epigastric discomfort, especially in diabetic patients or those with atypical presentations. The patient's morbid obesity and potential for cardiovascular risk factors make this a "do not miss" diagnosis.
Pulmonary Embolism: Severe, unexplained pain can sometimes be a presentation of pulmonary embolism, though typically, this would be associated with respiratory symptoms or signs of deep vein thrombosis.
Aortic Dissection: This is a rare but catastrophic condition that can present with severe, tearing chest or abdominal pain. Although the patient's pain is described as epigastric and not typical for aortic dissection, the severity and the potential for atypical presentations in certain populations make this a diagnosis not to be missed.

Mesenteric Ischemia: This condition involves insufficient blood flow to the intestines and can cause severe abdominal pain. It's more common in older patients or those with significant vascular disease but should be considered in the differential due to the severity of the patient's symptoms.
Diabetic Ketoacidosis (DKA): Although the patient is on a GLP-1 agonist, which might suggest managed diabetes, DKA can still occur, especially if there has been an interruption in insulin therapy or significant alcohol consumption leading to dehydration and ketoacidosis. The symptoms could include severe abdominal pain, among others.