I second the exercise suggestion. It’s really the #1 proven thing to lower the risk of diabetes and reverse pre-diabetes. Even if it’s just walking (which can also lower your stress levels).
The other thing is do whatever you can to lower your stress levels. Meditation has been shown to be effective in all kinds of health outcomes, so if you can do that, bonus. Stress has been shown to increase diabetes risk.
I think David’s diet suggestions sound smart, too, and you can adjust based on how your body feels.