Hi Melaniejane,
Your situation sounds really challenging and i think you should ask your doctor for some support as a matter of urgency. Your son sounds frightened of the risk of hypoglycemia, but this is easily avoidable once the diabetes is under control. If he keeps a packet of sweets with him, he will quickly learn to spot the signs of low blood sugar and treat them quickly and easily.
What is a much more immediate risk is diabetic ketoacidosis. His blood sugar wil be dangerously high without his insulin and this will attack every organ in his body, causing permanent damage if not caught quickly. DKA is the commonest cause of death in diabetics under the age of 20.
Is he frightened of the injections? This is fairly common at first, but he will quickly learn how to do this painlesly. As Sue said, he really has no other choice.
All the best,
fergus