Do make sure he keeps testing his BGs now, 3 months is rather a long time to wait if they don't fall, or start rising again. It would be good to record them so his GP can see the trends.
@MH2010 things have started to progress. Keeping a record of blood sugar results is an excellent idea. That will give you evidence of highs and lows. I hope the increased metformin helps.
After increasing the amount of Metformin hubby is taking, highest blood yesterday was 10.4 and before bed this morning (still on night shift), it was 7.2.
Thank you all for your help and for stopping me from having a mental breakdown!