Hi and welcome! Wow! You've brought your blood sugar down from a critical high! And you've done that on diet, exercise and metformin? Good for you!
I can't suggest your changing the metformin dosage because I'm not a doctor (no one here is), so I'll have to advise you to ask your doctor. Please call the doctor's office and discuss all this with him/her.
You will need to keep up the change in lifestyle as unfortunately, our blood sugar problems will not disappear when we get them down to 'normal' levels. If your doctor agrees for you to go back to metformin twice a day, that would certainly help the blood sugar come a little lower.
You've done so well! Really! Keep us updated about
what the doctor says!