I personally do not find it bizarre to have fatigue on a longish water only fast. If you think about what is happening in your body, and for insulin resistant type twos it is arguably really good things - the fact that you don't have a lot of energy is understandable - fat burning or nae. That's what I think anyway, and from my own experience with fasting.
Individual responses to fasting is like the differences to all the metabolic functions, including to exercise and to medications - there is enormous variations amongst people with diabetes, and the normal population too I gather.
But saying that - there are things that can really help iron out those individual and negative differences when fasting - switching over to bone broth, (electrolytes - those pesky things), salt (ditto). Maybe having some herb tea, and trying different ones. And journaling your response to see what is happening to you individually in response to the small changes. They might not give you much more energy, but they very well make you feel a whole lot better.