This may be taking you off at a tangent, but thinking about the lack of hmmm, responsiveness of your GP to your elevated levels, just thought I'd mention something interesting - though it may be old news to some of the experienced folk on this forum.
I had a T2 diagnosis a few years ago (I've only just switched to hardcore combat - using very low carb/low cal stint at present with excellent progress but a long way to go). Anyway, one printout that I had from test results contained some HDL/LDL/Trig info from some 3 years prior to my diagnosis. I've been looking into research (lots of research!) and found that the HLD/Trig ratio can indicate important insulin resistance well before you have any kind of diagnosis.
I'm a newbie, so hope I can post this link. I came across website
https://www.thebloodcode.com/calculators/ which, if you plug in your HDL/Trig values (it uses the US mg/dl but gives you a converter for international units mmol/L). It gives you an optimal range ratio, a range that shows some insulin resistance, and then a high level resistance mark. At that time, 3 years before diagnosis, my blood glucose was completely normal range (4.7), but this ratio showed insulin resistance. If I had known THEN what I know now, I think I would have taken different steps and not ended up with a T2 diagnosis that I am now determined to fight into remission.
Best wishes to you.