Numbers in themselves don't mean much because different people react in different ways so that they are more or less sensitive. Some respond optimally to much higher levels, some to quite low levels and there are so many things going on in the body. My levels are around 2,000-4,000 pg/ml and I feel the best I felt, it just depends on the individual. Estradiol levels also fluctuate from one day to another, especially on injections.
Diabetes is caused by insulin resistance caused by excess insulin over time, some sort of desensitization. What raises insulin? Carbohydrates, plain and and simple. Like pasta, bread, lentils, corn, juice, sugar, oatmeal, fruits over time can also lead to insulin resistance. I know several people, including physicians who cured their diabetes Type 2 by simply cutting down on carbs and increasing their fats to compensate. Check out Mary Vernon.
I also read in studies that progesterone increases insulin resistance while estradiol improves insulin sensitivity but glad your P is improving things.

p.s.: not a doctor, just someone reporting what I know and read. Always consult health professionals.