64yo overweight male, dmx5yr, not following diet so meds now. Losing weight but drinking lots of water. Why?

Look at blood sugar. Drinking lots of water, frequent urination, and weight loss are cardinal signs of poorly controlled diabetes. You need to be checking your blood sugar at home. Are the readings high? Glucose has a diuretic effect, and most people start to spill glucose into the urine when the blood sugar is in the 160-180 mg/dl range. If you are having high sugars, you need to contact your doctor for advice.