@midiman @HSSS has provided a good answer to your question on what is a LCHF diet. I can reiterate in my case it seems to have been greatly successful. You learn a lot on these forums. It seems to me ones chances of success vary a lot but I have had good results, possibly as I am pretty sure I was not diabetic for too long before my diagnosis. In my case in my first 3 months I mostly followed NHS guidelines (eating "healthy" carbs but eliminating sugar, potatoes, rice and bread) and I lost a ton of weight but did not get my HbA1c down as much as hoped, so went truely low carb at that point which achieved the desired result. Lately I have not been so rigorous with the carbs but its still usually under 50 g / day.
With regard to the HbA1c test I was disappointed but understanding at not being able to have my 3 month scheduled test at my surgery. Looking around I found a commercial organisation called
LetsGetChecked.com which provides a service including a blood sample collection kit for £39. I tried this out earlier this week and was gratified to see the labs I had to send the sample to ("The Doctors Laboratory") are members of a large scale medical diagnostics operation in central London which is in partnership with 2 NHS trusts (Royal Free and UCL). Anyhow the home blood collection was a bit gruesome (you had to collect rather a lot using a pin prick device. I was glad I take regular samples so knew which fingers were the most "productive"), but I was impressed with the processing - I mailed off the sample just after taking it, early this Monday morning and I got my results Tuesday afternoon. The result was what I expected/hoped (5.7% which is 39 mmol/mol, just 1 point above my previous result. For some reason they use the old DCCT units). I have since emailed the result to my medical practice explaining what I had done. My regular practice nurse has just called me up to discuss the results. I noticed she accepted the result as likely being accurate but has not updated my medical record with this reading, though she did put in my reported current body weight. Anyhow it seems to me, if you can afford it, this home testing method is well worth doing as an adequate substitute for this non-essential test. The price is not outrageous and the result I got was consistent with what I was expecting. Obviously its a commercial organisation and the blood collection method is not at all the same as one taken by a medical practitioner in a controlled environment, but I probably will do this again in 3 months if we are still in lockdown.
I don't think I said earlier, but I am currently taking metformin - 500 mg bd (when I was diagnosed 9 months ago I was put onto 850 mg bd. This was reduced after my tests 3 months ago). My nurse advised today to continue this for the next 3 months and then to halve the dose if my HbA1c is sustained.