Just text my boss to say I won't be in today (been feeling bad for a few days - tonsillitis+ diabetes) thus triggering a first-stage attendance hearing.
So I'm feeling pretty bad, guilty and on top of that extremely tired and well, poorly.
If you are in the US, diabetes is covered by the Americans with disabilities act and there are laws governing what kind of accommodations your employer is legally obligated to make for you.
Diabetes comes with needing extra or extended sick time and is not likely an unreasonable accommodation for your employer to make.