My understanding of insulin resistance is as follows:
Insulin acts like a key to open the door of cells so that they can utilize the glucose in the blood stream. In insulin-resistant people, it's as if the cells' doors had sticky locks, and the keys don't go in well; thus, you need more insulin to enable the blood glucose to get into the cells.
I've never heard the term "insulin-resistant" applied to people with hypoglycemia, although of course I haven't heard everything,
However, what I HAVE heard about hypoglycemia is that the pancreas, for some reason, OVER-produces insulin in response to an increase in blood glucose, thereby using up the glucose too quickly and causing a corresponding drop in blood sugar.
Some people with hypoglycemia go on to develop diabetes because the overproduction of insulin wears out the islet cells in the pancreas and eventually the body can no longer produce enough insulin.