Please forgive my ignorance, how is it possible that you lived until your thirties without knowing you have T1D?
"Identifying most people with T1D continue to secrete varying amounts of insulin and C-peptides for decades after initial diagnosis:
https://www.healthline.com/diabetesmine/dr-faustmans-controv...
See below for my deeper response on these and other issues:
It takes a genetic predisposition and a trigger - perhaps a virus? - for your immune system to start eating your pancreas' insulin-producing cells.
The old labels of "juvenile diabetes" etc. are as unhelpful as the notion it's caused by obesity.