When your numbers are that high you tend to lose weight. Your blood is very thick with sugar molecules that are attached to your red blood cells. Your insulin resistance is very high- the result is that all of the sugar is in your blood, needed glucose cannot get into your cells to meet your energy needs, so your body thinks it is starving and starts to digest your muscles and fat reserves to meet that need - you lose weight even though you may be eating a lot of food. Once your numbers start to come down, and stay down-you will stop losing weight so rapidly. In fact, as your cells begin to permit the entry of nutrient glucose again, you may even regain some of that weight.
Prednisone will tend to bloat you- so you should lose that water weight as the drug leaves your system.
Since your numbers have been so high, you may feel really awful ( shaky, sweaty, nervous, maybe even mean and nasty) when you drop down to more normal numbers. A normal range for non-diabetics is 65-99, so you are in no medical danger- even though you may feel gross. My blood sugars are almost always in the 70-90 range now, and I feel great.
Januvia is a newer oral medicine for type 2 diabetics. It helps us to make better use of the insulin that we make. It has helped me to maintain stable numbers in a non-diabetic range- whether I eat a few too many carbs or exercise too vigorously - I am always stable, and always in-range. It is a great drug for me! No side effects or weight gain for me either.
I'm sure you're going to be doing great soon- patience and persistence go a long way towards gaining and maintaining control!