Tricky to deal with, and you and he have my utmost sympathy. My nephew was diagnosed T1 4 months ago, aged 17, and he has problems managing his attitude to it.
That's harder on his mother and father than he realises but they're very slowly learning to deal with it.
There's one situation you might think about looking out for, although I've not got any quick answer to it: My nephew has said several times recently that he feels 'over-managed' and 'under the microscope' when in fact his mum and dad are simply asking (albeit fairly frequently) 'how he is'. I know that's because they're on a steep learning curve as well as him and they're worried they'll not be able to spot 'danger signs'. For his part, he says 'he'll tell them if he's not feeling well and to stop asking him about it'.
Neither side have yet got it right and a few times have had rows / stopped talking to each other because of it. He's a bright, well-balanced adolescent and they're good, caring parents, but somehow they've not yet managed to reconcile their respective positions. Neither side feels they should back off and that's often ended in stalemate.
The other thing is understanding: Depending on his attitude, it will take your son quite some time to get his head around how his illness works and appreciate the illogical and unpredictable way it sometimes behaves. It won't always play by the rules and he'll feel frustrated that he can't control it, even though he'll think he's doing everything right. Again, I've seen my nephew with tears of frustration in his eyes because of this and I can understand how he feels. Although reading up on diabetes and talking to others will help you to gradually understand what's going on, you've all got to be careful not to overload (or be overloaded by others), by trying to understand it too quickly.
There are plenty of examples of those who have gone through this and have come out the other side. It might be useful for your son to realise this as well. It changes lives but, with good management and a steady approach, it needn't be anything like as bad as he probably thinks it is now. There are a lot of accomplished people who suffer diabetes but have still gone on to make a success of their lives - it might be worth looking up a few of them and wondering how on earth they managed it. I know I was surprised.
Good luck. Please let us know how you're getting on and don't worry about asking for advice - there's usually plenty of people on here who are looking to help.