Hi Kitty,
Just so I get it, your son is diabetic, your girl is not and you are not either? I'm sure there are a load of parents on the youth forum here who can talk to you about parenting a diabetic. My wife might have some insights as well as she parents me a bit sometimes.
I hope you can get some help/advice on here from them. Your boy is about to enter a dangerous period of his life as rebellion against the diagnosis and poor control is a serious issue. Teenagers are challenging and invincible (at least they believe so) and will make some bad choices. For some these have little effect but he may well have to grow up a bit faster than his peers. I don't want to scaremonger as if well managed he can have a great exciting life as he grows into a young man but I lived with a type 1 diabetic all through uni and now I have LADA and understand I look back on how we lived and its likely he did himself some not inconsiderable damage.
Good luck with it all. Having a mum who understands his illness can only be a positive though.
TTP