Hi
My son was diagnosed in towards the end of Yr 6, so within a few months he was not only learning to cope with the condition, but preparing to move to secondary school too.
Looking back, I would say it took a long while for him to adjust to his condition. He was very angry and frightened to begin with. He got cross with school teachers and tended to have panic attacks when his blood sugars went low.
I certainly noticed that my son's emotions were all over the place for many months after diagnosis - he just wasn't the same person he had been before. Unfortunately, erratic blood sugars do affect moods, so there is both the emotional impact of the diagnosis and the effect of the sugars too - Double-whammy!
However, by the end of the year, things were beginning to look better and he felt much more confident that people at school understood his needs and would support him. He began to enjoy school again . It took even longer for him to be confident about being in places other than school or home and even now, this is still a work-in-progress situation as he spends more time out with his friends.
It is almost 4 years since my son was diagnosed and he is back to being the happy and relaxed person he used to be. He no longer resents his diabetes (well, not often anyway!) and although he wishes it were otherwise, he does completely accept the changes. It made a big difference when my son switched from injections to an insulin pump too because that made his daily life much more normal and flexible.
If your diagnosis was weeks or months ago, probably people around you think that it's old news and no longer a drama. Personally, I would say it could remain a big deal for you for some time to come and that different people take their own time to recover from the trauma - so just don't expect too much of yourself too soon. Typically, after any life-changing trauma, there is a phase of shock, a phase of denial (anger) and there should eventually a phase of acceptance. Some people might need expert help if they get stuck in the shock/denial phases and just can't move on towards acceptance.