Yes, I have a machine which was recently checked for accuracy. I used the machine to check the blood sugar levels. I feel these symptoms about two or three times a month; the blood sugar levels can range from 155 to 195 when I test. Those are not always fasting levels; my before breakfast (fasting) levels range from 140 (rare) to 180.
The metformin was added in December. It has helped the excessive facial sweating from the neuropathy, but does not help the other symptoms. I still get the sweating on the back of my head and neck when the other symptoms appear.
It feels like classic symptoms of low blood sugar, but the numbers never reflect that.