Aww Chuck! What a proud dad you are and you have reason to be! Good for your son. And good for you to be wise about your initial reaction. You sound like a great dad!
You may have already done this, but tell your son you're proud of him. I know there have been times in my life that Dad was proud of me, but he never told me. I grew up thinking he didn't care. I've since found out from other people that Dad was proud of me on several occasions because he told them so. But he has yet to tell me. Of course, now that I'm DFed he'll never say anything good to me.
So take the time to tell your son 'thank you' and 'I'm proud of you'...I can guarantee it - he NEEDS and WANTS to hear it!
Andi