Some people may well question whether, with an HBA1C of 40, you still need to be on Metformin. After all, if you presented to your doctor as a new patient and tested at 40 you would be out of even the pre-diabetic range and would be unlikely to be prescribed anything other than lifestyle caution.
On the wider point about weight loss (and your numbers are fantastic by the way) do you feel like you’ve still got more to lose? If so, are we talking a couple of pounds or a couple of stone. If it’s the latter it’s going to be frustratingly slow. Also, to help people advise it may be useful to understand what you’re eating on the days when you’re not fasting.
Whatever happens, well done, be proud and don’t let these kind of numbers get you down at all!