Welcome
@Rachel L , sorry to hear about your son but welcome to the forum. There is a lot to take in when first diagnosed so the best thing to do is read up on the diagnosis. I got a free book from Diabetes UK which told me all the basics and i went from there. Ask questions, no question is too silly. If your son was started on insulin yesterday it will take time to have an effect, depending on what he is on and whether that suits him. As
@Inka says, it takes time to get the dose right and he will learn how to adjust it when needs be. Any questions you have, fears or even a rant about how things are, come on here. We all are living with diabetes/parents of children with diabetes and there is a huge wealth of knowledge here from people who live with it every day and we understand.