Hiya
I'm not a child nor the mother of one - however I'm here to tell you several things
1. T1 diabetes does not automatically mean you will have a shorter life. OK I wasn't diagnosed till I was 22, but I'm 63 now and - as far as I and my doctors are aware - complication free. But it is fair to say that people have had what seems to be marvellous control and still have complications so sometimes you have to accept that it is just the disease and the genes and whatever, it isn't ALWAYS because people 'haven't done it right'.
Much like T2 not ONLY being caused through being overweight/eating the wrong stuff. Sometimes, for whatever reason, the short straw happens to be yours.
This condition is far less of a death sentence than being born in the first place! (think about it LOL)
They do have to tell you upfront about all the carp things that MIGHT happen that they know about, though - think how annoyed you'd be as an adult, to discover some years down the line that something that's happened to you is actually linked to diabetes - much like all the chaps who've had successful prostate cancer treatment in the past and thought they were OK and seen the back of it - only to find they now have Parkinson's Disease - and that there is a link? (to use a comparison in the news at the moment)
2. Being angry is good! It's right, it should happen! - you are normal ! - have a read of this if you doubt me - you will go through every one of these stages, one by one.
http://www.diabetes-support.org.uk/info/?page_id=50
Importantly - so will your child at some stage. You can express how you feel, and obviously have the sense to know you aren't alone and eg ask on here or your medics for help with it. Children/teenagers/young adults often don't have that maturity - sometimes adults don't either. And it's something you have to work through - it does wane as time goes on - it's been years and years since I had a 'Why me?' day now, but it could happen again, especially if I'm having a hard time with something else.
Bear that in mind - you can't necessarily head it off at the pass, but recognise it when it happens and understand it.
Good luck to you and your children.