Well - I lowered my intake of carbs and just watched my levels drop back to normal.
I had decades of 'education' about what I should eat and what I should do - I was hugely overweight and felt far older than I ought to have - it was all because my glucose levels had been high for a long time due to the bad advice and all those 'healthy' carbs.
For a plain ordinary type 2 diabetic eating a low carb diet is all it takes.
There are lots of variations though, to make things more interesting, but I have had too much of interesting times.