I’ve seen other studies that show people suffering with candida have poor glycaemic control. Hypothyroidism is one potential factor, and also seems to be a common issue in candida overgrowth. Like you say, there’s definitely a chicken and egg scenario here, but doing what you can to treat any existing problems in concurrence with the protocol isn’t a bad idea.
You wouldn’t want to use insulin unless you were diabetic. You’re already eating a low-GI diet, which controls blood sugar spikes. Resistance exercise can also improve insulin sensitivity by depleting muscles of glycogen. This makes them eager to take in available glucose, which helps to lower blood sugar when you eat carbs. I’d also avoid ketosis if you do exercise or have any hormone imbalances, especially thyroid issues.