Hi
@Jaz132
Me, my diabetes, my insulin and my Libres have done lots of flying together and never had any problems.
The usual advice is to get a letter from your doctor (unlike a GP, a hospital based doctor or DSN don't charge for these) which will explain that you must keep all your diabetes goodies with you at all times. To be honest, in 20 years and literally, hundreds of flights, I have shown my now very tattered letter once.
Some people pre-empt any questions by telling security. I chose not to spread personal information unnecessarily and they hardly ever ask.
If you have any unused insulin cartridges (I assume you use reusable pens), it is probably worth putting these in a clear plastic bag as some security guys are a little over eager when it comes to liquid.
Not security related but from my years of experience, my top tip is to make sure your hypo treatment is with you in your seat - not in the overhead locker with the rest of your diabetes kit (do not put it in the hold). I once had a hypo whilst taking off and had to endure the wrath of the cabin crew by standing up to get my hypo treatment out. Not a mistake I made twice.