Aww, bless you, it’s hard when it’s your child isn‘t it. Unfortunately he’s at an age when he’s discovering his own ways of doing things and won’t appreciate parental input all the time. My daughter is 17 now and I’m just trying to let her get on with it on her own, they have to find their own way (and unfortunately sometimes that means learning the hard way). My daughter was diagnosed 11 years ago so I’ve had much more time to come to terms with it, but it took me a while in the beginning to learn to relax. It’s also hard now not to comment every time I hear a Dexcom alarm going off, but I do try!
All you can do is be there for him if he needs it, and try not to nag in the meantime. Make sure you talk to him about things other than diabetes and don’t ask him about it all the time. You’ve offered to go to appointments but he doesn’t want to you to, so don‘t push it. What about his girlfriend, does she understand the situation? Maybe he’d prefer her to go with him? Or maybe he just wants to deal with it his way, and if he’s 18 there’s not much you can do about that I don’t think. You could try having a word with the girlfriend, but if that doesn’t go down well then best to leave it be.
Try to learn not to obsess about it, I know that’s hard but take it a day at a time. Blood sugars of 10 are not ideal but they aren’t terrible either. Same with the HbA1c, my mum’s is higher than that and she just carries on happily! Not that I’d recommend that, but it’s her body her diabetes, and as a DSN once said to me, “there’s no point trying to manage everything perfectly if that’s all you think about, you have to enjoy life as well.” Try to step back and let him do it his own way, and he’ll be fine. It sounds like he’s not passing out all over the place or repeatedly being admitted to hospital, so it could be a lot worse!