First think in the morning, blood sugars are high because of the
Dawn Phenomenon (also called Liver Dump). Hormones cause the liver to release glucose into the blood early morning. Sugar levels usually drop afterwards, so if you wait a couple of hours before eating you should see a drop.
Metformin takes a few days to take effect. If may only drop your blood sugar by about 1-2. A much more effective way of reducing your blood sugar is by going on a Low Carb High Fat (LCHF) diet. That means cutting out bread, breakfast cereals, potatoes, rice, pasta and stop drinking fruit juice. See
https://www.dietdoctor.com/ for examples of what you can eat.