A 60-year-old man with se...

A 60-year-old man presented with a known history of type 2 diabetes, hypertension, ischemic heart disease with severe left ventricular dysfunction, and rheumatoid arthritis. He presented with severe mucositis of the oral cavity, dysphagia for 1 day, and laboratory findings of pancytopenia, deranged renal function tests, hyperglycemia, and the presence of urine ketones. What will be the diagnosis?