Hi Georgia and welcome to the forum 🙂
Yes unfortunately type 1 rules you out of the Armed Forces, but it needn't rule you out of flying planes if that interests you. My son and I went to a really interesting day run by JDRF last year: "Flying with Diabetes", where the main speaker was a man who had been in the RAF when he developed type 1 and had to leave, but he has campaigned for the rights of people with type 1 to fly (not military jets though!), and has achieved some amazing feats.
Do get the Ragnar Hanas book if you haven't already, it's the best source of info out there.