I switched to a low carb (25g or less) three years ago and was able to reverse my type 2 diabetes within the first 6 months to 1 year. I get my A1C tested every 6 months and intermittently wear a CGM to fine-tune my eating habits. For example: Eating ½ cup of raw carrots alone raises my blood glucose levels by 45 points (mg/dl) but eating them with fat and or protein only raises it by 20 points.
Carrots are normally 7% sugar, so a spike is to be expected unless diminished by eating stuff first. Veg first usually works best (e.g. salad as a starter). Fat is also good but I admit that's hard to do at Breakfast but eating sugar/carbs cereal first is generally not best. Have you tried low carb cereals (usually nuts/seeds based)? I found 15% carb cereal from Paleo works fine but needs to be followed with some sugar for energy (e.g. Berries)