They aren’t low carb
Also just to make it trickier some if us react particularly strongly to certain types of carb, over and above what you’d expect from the carb count alone. I don’t know why. Maybe we have a biome that struggles with certain foods and the way we break them down (just a guess). For some that might be grains, or beans or carrots or onions. It might be none of those and we have predictable rises.
As for medication. You didn’t become diabetic overnight and it’ll take a little while to find remission. Months not days usually. But it’s all progress. You may or may not need medication to help you further. Your plan of seeing where these life changes get you in 3 months is a good one. We don’t all need that extra help, some do, sometimes longer term, sometimes just for a while. The more you can do long term with diet and lifestyle, and maintain it, the less medication you will need over your lifetime and the longer it’ll be before you need it (if ever). Metfomin will not prevent it being progressive without the lifestyle part to go with it.