Best non invasive blood glucose monitor

Before you go the very expensive CGM route, I would suggest you experiment further with finger pricking. If you have your own lancing device you can set the depth to a minimum. There is something wrong if your finger is sore for more than a few seconds.

I don't think non-invasive monitors exist, except for pee strips, which only tells you if you have been below or above circa 11mmol/l some hours before you test.
Agree with @Mr_Pot , try a pricker and set it to a low number. And use the side of your finger instead of the middle.

You know, there are no non-invasive blood sugar testing devices. None exist.

To test blood sugar, you need a blood sample. Getting that is invasive.

For cgm, a sensor is shoved into your skins and it’ll stay there. That’s invasive too. Another thing to keep in mind is that the interstitial fluid it’s testing isn’t blood sugar. So it’s a different kind of reading. For some this works fine; others not so much.

Glucowatch was supposed to be what you’re looking for! But it was completely non-effective. It worked more like a mood ring and was non-effective in determining any kind of reality with blood sugar (I owned a glucowatch... it was worthless.)

So a non-invasive blood sugar testing system doesn’t exist. For those systems that say you won’t have to poke your finger you are still going to have to poke something, like your arm. Blood sugar testing requires blood.

Sorry for the bad news. Real technology to do what you’re looking for doesn’t yet exist.