Hi my dear,
you have all my sympathy. Here is something I can suggest out of my experience (a long experience, as I've lived with T1 for 35 years now). I'm telling you what works for me, but of course you may chose otherwise. So please don't simply follow what I'm writing here, should you feel like it, but do think it through with your parents and take their advice first.
Ok, here we go.
a. Use the name of our condition, not the name of one of its symptoms. Our disease has a perfectly honest and short name, which is BCA (try and google this up). Diabetes (chronically high BS) is a symptom of BCA. And of oh, so many other conditions! I always use the name BCA with dumb people so as to send them the first and most important message: please realize that you don't know anything about it. It's something totally unknown to you and you have to learn a lot about it before you even think of telling or doing anything about me.
b. Then you can say, like, 'chronically high BS is a symptom of my condition. That's why some people call it T1 diabetes. But this is rather inaccurate.'
c. To explain the difference between T1 and T2, you may like to try something like this: 'T2 is something a T1 simply cannot have. I will never get it, not even later in my life. It's outright impossible, because BCA-affected people actually lack the part of the body which gets impaired in T2.'
I usually try to stress this further and my favourite example is: 'You can compare T2 to varicose veins and T1 with no legs at all (my 'legs' having been cut off by my guardian angel – immune system – when he went mad). T2 and T1 share a symptom: they can't walk well. True. But while 'varicose' might get better, there's no way a T1 will get their 'legs' back, no matter what they eat, drink, do, stop doing etc. They will always need crutches (insulin shots) to walk around.'
I hope this can help somehow. A hug, and best wishes!