Hello there... Replying ur Q, lets see I was 7 yo when I got it and now Im 30, so its been 23 years with it though just a month ago Im taking care... My advice wouldbe to change ur food choices as often as possible, good luck!
Diagnosed at 3, 24 years ago. Plenty of evidence I was diabetic since my first year of life though. Local health team were idiots and said 'nothing's wrong it's not diabetes' for over a year. By then I weighed half what I should and was going in and out of a coma. Mum took me to the GP because she had enough of the hospital, and he diagnosed pretty much on the spot and called an ambulance.
Diagnosed June 2013 at the grand age of 49. Stayed in various hospitals over the last year and the amount of nurses that say " you can't be type 1 you're too old " Gotta laugh.