Thanks for the tag
@Antje77
Yeah I fly a lot and have no problems.
Needles are too small to be seen by security so there is no need to tell them (unless you want to).
Libre is not affected and you don't have to tell anyone as it has never set off alarms (unless you want to).
Insulin is a liquid so it needs to be in the clear plastic bag along with shower gel, etc..When I remember to put it there, no one asks about it.
I do not carry original boxes or prescription and am not asked.
I do have a letter from my doc which u have shown once in 20 years but lives with my passport so a handy insurance just in case.
The letter only covers me so I never give my diabetes kit to anyone else to carry as that may risk it being confiscated. That said, most of my flying is for work and I travel alone so it is not an option
All of my diabetes kit (at least twice as much as I think I will meed) is carried in my hand luggage. The insulin may not like the hold conditions but, more importantly, my bags may be delayed.
This approach has treated me well traveling Africa, America, Middle East, Europe, China, ...
As
@EmmaK_2907 says, you will be fine. Travel is a perfectly normal thing to do and diabetes should not stop you.
If you are anxious, you can get a sunflower lanyard.