Hi,
I'm sorry to hear about your little boy. Having children is challenging at the best of times, let alone when you throw a medical condition like diabetes into the mix.
I have 3 children as well, 2 of which have type 1. Generally they are well controlled but I find that they can be very moody if their blood sugars are elevated and also when their readings are volatile. My husband also has diabetes and I notice that he gets a bit short tempered when he is in the low 4's ( i can pick up on these warning signs before he does). You haven't mentioned whether your son has good control, but I suspect if he is eating things behind your back and not taking insulin to accommodate this, then his blood sugars may be high prior to meal times.
With regard Easter I don't know what you allowed your son, but mine did have a couple of eggs which they had with their meal (as a pudding). We don't really have many foods off limits, but tend to give treats as part of a meal, rather than as a snack. It is very difficult though especially when you have other children in the house. My 2 even get jealous of each other if one of them has a jelly baby because their bg is on the low side!
It sounds like your son is finding it hard to accept his condition. Speak with your DN about the issues you are facing and she can make sure that your son and you get the support you need. Hope you can resolve these issues soon. Leggott