I’ve been diagnosed as type 2 diabetic though I’m not sure

Yes, the fact that your blood sugar is this high can contribute to your depleted energy, for two reasons. While the blood sugar is elevated in diabetes, the cells have low amounts of sugar. The primary function of insulin is to facilitate transport of insulin into the cells of the body, so when there is an inadequate amount of insulin or function of insulin, the cells are somewhat starved of sugar. Before insulin injections were invented, type 1 diabetics looked like they were starving to death, because they essentially were starving to death, even with sky-high blood sugars.

Elevated blood sugar also causes dehydration, because the high blood sugars cause excess urine formation, and the dehydration can contribute to poor energy levels.

Yes, insulin will get your blood sugar down more swiftly, and that is true for every type of diabetes. If someone has a diabetic emergency requiring hospitalization (diabetic ketoacidosis in a type 1 diabetic or hyperosmolar coma in a type 2 diabetic), insulin treatment is standard to get the blood sugar down quickly. In addition, insulin has the greater potential for lowering HgbA1c than other treatments. Since most people would rather avoid shots, doctors will usually try other medicine first, when possible, but insulin clearly will work more quickly and have a greater effect on HgbA1c.