Hi
@Kilchoman
what country do you live in? And what is your HbA1c? Depending on how high it is, you may fall into the extremely high risk group.
This is where you can find the UK
www.gov.uk Information on social distancing and shielding the vulnerable.
Depending on your HbA1c (and blood glucose levels of 20-24mmol/l suggest you are likely to have a high HbA1c) you may be in the extremely high risk group.
I suggest you discuss this with your Occupational Health team, and your doctor. If you ask your employer to provide written evidence of the guidance they are using, you will be better placed to understand their decision, and fight it, if appropriate.
it may also help if you find out what PPE you will be given, and the social distancing conditions under which you will be working.
As to your statement that you have a low carb way of eating... the diet you describe is carb heavy. Maybe reconsider your diet, with a view to lowering your blood glucose, or contact your doc for a major medication review/overhaul, since those numbers are likely to put you at increased risk of diabetic complications, over time.
Hope that helps. And good luck with dealing with your doc and occupational health.