A CGM is a continuous glucose monitor. The HbA1c theoretically should tell you what your average daily glucose is. If you look at 6.0 here:
http://www.ngsp.org/A1ceAG.asp
You’ll see that’s about 126 mg/dL (US units). If you take your blood glucose, and you get a bunch of 100s (or less) over the course of a day, you know your HbA1c is reading high.
The easiest way to do this is with a CGM, but they are expensive and hard to get (at least in the US).
Unfortunately, decaf coffee can raise trigs in some people:
As for fats and trying to change your values, I personally wouldn’t even attempt it. Your values are so high, that whatever change you make is unlikely to make much of a difference. And if your carotid artery scan was good, then does it really matter what your LDL is?
If you want to change LDL, just eat white bread:
This will, of course, ruin your trigs.