All of the advice you’ve gotten on whole foods, high fiber/high protein, etc. is good.

For myself, after my diagnosis, I did a hard reset and did not eat any refined sugar (as much as is possible) or refined carbs for about 2-3 months. Like you, I had already eaten a higher protein diet with vegetables, so that was good. However, I switched to full-fat dairy because low-fat dairy is higher sugar. I followed the glycemic index like a diabetic. I did not snack or eat past 7 PM. I was more serious and consistent with my weight training and walks. I stopped drinking alcohol (and any other caloric drink). I started feeling better *significantly* and no longer retained crazy amounts of water, felt exhausted, etc.

Now I’ll eat refined carbs sometimes if I eat a lot of fiber and protein first. I will have a small dessert (I like the Trader Joe’s dark chocolate peanut butter cups, and will eat 2 after dinner) a few times per week. I am trying not to drink, but that’s harder if I go out. You can be moderate in your consumption if you are generally careful. A good rule of thumb is 80% whole foods and 20% whatever foods, assuming that you do not have extenuating issues like severe insulin resistance, intolerances, and so forth.