Hi
It sounds asif they are concerned but don't want to alarm you. I think you need to try and talk to them again about it, perhaps you could say you will worry more if you think they're not being completely upfront with you? If you do have diabetes it isn't the end of the world, my 15 yr old daughter has it, so does her little sister, and they are fine.
Any questions,, ask away, I will look in again on the forum tomorrow evening, or someone else will help you.
Best wishes
Sue