What is your general macro mix? Or perhaps the easiest number to work with: about what percentage of your daily calories come from carbs IF you are not in a calorie surplus or deficit?
Even though I prefer a baseline of about 25% carbs and 50% fat, when I try to reduce weight I will cut mostly fat from my maintenance, and when I train I will add mostly carbs. When carbs get below 30% on a maintenance diet, fasting blood sugar actually tends to ruse a little bit because muscles stay loaded with fatty acids to spare glucose for the brain and nervous system. For non-insulin resistant people that will tend to push their fasting blood sugar up to the 90s (non pathologically) but like I said before, cutting fat for 48-72 hours will burn fatty acids out of muscles and open them up to take in carbs more easily and if you train hard, you can get your muscles burning fat AND staying insulin sensitive afterwards.
Also, by the way, Alcohol and Fructose, (above a certain baseline, about 4% of maintenance calories) makes the liver more insulin resistant, and Fructose has an independent ability to raise A1C without showing up in blood sugar tests. Keeping fructose under about 25 grams a day can lower A1C by .3 to .5 without any change in blood sugar levels, for example, someone with a 110 average (round the clock) blood sugar will typically have an A1C of about 5.5, but if they eat high fructose it can be 5.7-5.8 and if they eat minimal fructose it can be 5.2-5.3. This is because fructose has 10x the glycosylating ability as glucose even though it is only present in the blood at about 1% of the level (about 1 mg/dl).
Another thing that people don’t realize is that high cortisol levels from stress, illness or intense fatiguing exercise, OR from inflammatory/allergenic foods (Omega 6 oils, wheat, legumes as well as other grains and foods to a lesser extend) makes you insulin resistant because cortisol makes blocks insulin’s effects and makes you have to release MORE to manage blood sugar levels. This makes you even more insulin resistant because your cells get overexposed to insulin. It also means that your body is flooded with insulin at night which blocks growth hormone, which prevents healing, which…raises cortisol levels and makes your more insulin resistant. In your case, you may have genetic or autoimmine insulin receptor resistance, but people can progress toward T2D even without a genetic receptor flaw and the basic mechanism is inflammation—>cortisol---->insulin resistance---->growth hormone blocked----->inflammation (even though growth hormone is actually inflammatory, it heals microtrauma which ends up helping your body to need less cortisol to counter chronic inflammation.
Personally, I used vanadium in the 90s, and my organic chemistry teacher told me about chromium around that time too, but besides getting a baseline level, I would say that the science does not suggest a major impact on insulin sensitivity. Cinnamon does increase insulin sensitivity. Also anything that reduces cortisol. I am trying Circumin and I was skeptical. I think has reduced some of my inflammation hot spots. Also, you may know that adding a sour element to every meal slows down the rate of blood sugar rise. A teaspoon of vinegar before a meal works well. Also, anytime you can be active for 15 minutes before breakfast, and for 15 minutes after your last meal of the day will improve insulin sensitivity, and a walk after an early dinner will help get your insulin levels down for bedtime so that you can get your “early night” growth hormone release. Since your body is probably releasing a significant amount of insulin at night just to keep fasting blood sugar good, I might consider taking Indigo 3g before bed, but definitely having some kind of evening activity that improves insulin sensitivity would help. Swimming may be the absolute best. My son has type 1 diabetes and swimming for an hour can make him more insulin sensitive all night long (I often have to turn off his basal insulin if he swims in the evening).