New to group, on Metformin since March

Hi to all! I have been prediabetic, per my labs, for several years. In March, my A1C was 6.9 and my fasting glucose was 160, so I was diagnosed as diabetic.I am retired, and a former shift worker, and I only sleep about 3 hours a night. Weight loss and exercise are two areas where I can focus on improving my health.
I just joined a gym, and I am hoping that some cardio might induce me to sleep. My physician initially started me on ER Metformin 500mg, twice a day. After some gastro issues, he changed it to 500mg immediate release twice a day. I have had dietician guidance but I still crave carbs, especially at night.
My fasting test in the am is running high, 140 to 160. Are there any insomniacs that could give me some tips on how bring down my fasting numbers? I am excited to learn from others in the forum.