Hi, don't worry. Security won't be concerned in the least. I've never been asked for (or even thought about bringing) any evidence of diabetes or medication. Just keep all your medication and needles in cabin bags and pop your insulin in the clear bag with your liquids.
I'm not 100% sure of the protocol when it comes to getting spare CGMs through the scanners and whether they damage the CGMs - but check with the manufacturer website to see what they have to say, don't rely just on the responses here. That said, the one you are wearing might be picked up by the body scanner - if it is and you are patted down, point it out and tell them what it is. They are well used to them now, so it shouldn't be an issue.
Edit: I should have added that while I don't carry any evidence for getting through security, I do bring my repeat slips, but only so I can show what I am already on if I need healthcare while away and they can see what I'm already on and match or check for contra indicators.
Bon voyage.