So sorry your family has to deal with this. I am an adult and diagnosed with T1D as an adult. But I did parent a daughter who is now grown, so I understand some of your challenges although nor fully from your situation.
I have started listening to the podcast of a father of a T1D daughter, diagnosed at age 2. Scott Benner's podcasts give great insight to what it's like taking care of a T1D child. Check out his Arden's Day blog and podcast. Scott has a great manner and tact dealing with all the issues that are particular to a T1D child and family. Scott is a stay at home dad who remotely manages (using modern diabetes technology) his 11-year old daughter's diabetes even when she's away from home whether at school or playing with her softball team.
There are many TuD members, parents of T1D children, like @Lorraine above, that have walked this path before you. They all want to help you.
I've lived with T1D for 32 years this month. This disease sucks but there are many ways to make it suck way less. Knowledge is power; learn all you can about diabetes and insulin. You are now in a long game dealing with diabetes. The more you learn the better off you'll be.
But pace yourself! You have time to learn all you'll need to know. Learn a little each day and your knowledge will soon surpass many of the doctors, nurses, and diabetes educators that you'll now look to for advice. Find your peer community, whether it be here or possibly with a group focused on T1D parenting issues. With the advent of social media, peer support has really come into its own. Participate. It will be good for your spirit.
I could go on and on but I'll stop. Embrace this new life because you not only have no choice but you can help your son live a very normal and healthy life. He can grow to become anything he dreams of being!