Type 2 diabetes is a disease of too much insulin resistance. Insulin is a hormone that helps bring sugar from the blood into a cell. It's like a key to open the cell door and it helps to take sugar from the blood into the cell.
When you have insulin resistance/type 2 diabetes, the problem is not that there is less insulin, the problem is cells are not responding well for insulin. On the contrary, your body produces more insulin to ensure we can force the glucose from the blood into the cell.
This is very similar to a bull pulling a cart. When the weight is less the bull can easily pull the cart and move it from a to b. This is when your pancreas produces normal insulin to send a normal level of blood sugar from the blood to cells.
When you increase more weight on the cart, the bull to put more effort to pull the cart from A to B, this is like your Pancreas needing to produce more insulin to send more glucose coming into the blood into cells.
As you keep adding more weight on the cart, the bull becomes slow what we do it beat the Bull to put even more effort to pull the cart from A to B. This is when we take medication to force the pancreas to produce even more insulin to take the even more blood sugar from blood to cells.
As you keep adding more weight no matter how much you beat the Bull it will not be able to pull the cart, so the human also gets down the cart and pushes the cart to move from A to B. This is like when we take insulin injection as your pancreas is not able to make more insulin.
The problem here is not Bull or Insulin. In the first example, the problem is the load if you had normal weight. Similarly, for Type 2 diabetes, the problem is not with Insulin the problem is with the amount of sugar/glucose you put in your blood. If you don't control that then your system will break at some point in time.