Hi The Fugitive.
I was going to PM you but thought this maybe useful to some others aswell.
The "never been investigated" part really worries me.
As an insulin dependant diabetic for 35 years, i have some knowledge about low blood sugar levels. The symptoms you describe should start to be noticeable at around 70 mg/dL (3.9 mmol/L), i feel it earlier as i'm aware of the feeling.
At a level of 42 (2.3) there are lots of other things going on also and i advise you to make those around you to be aware of any personality changes etc. Loosing your temper, sluring of words, confusion, unstable on your feet, sweating. They can then let you know something is 'not right' before you start to notice yourself.
At levels below 70 (3.9) it is dangerous to drive or ride for yourself, passengers and other members of the public due to the above symptoms and also blurred vision.
I personally test my blood 6-8 times a day to avoid highs and lows.
If i knew you personally, i would go to a suitable pharmacy and buy you a glucose meter and a pack of 50 test strips, which if memory serves me can be purchased at around B1,750-B2,000 and test you twice a day at varying times eg, morning,midday,
evening, before meals, an hour after meals etc to get a picture of whats going on, and record the results so that you can show them to a doctor.
I hope this helps and take care pal.