I would seriously consider whether therapy is an option. It may be that something really short term would make a difference. Intense kids needs to learn to manage this stuff and I wouldn't just assume he'd grow out of it.

I found this book a helpful overview of child anxiety. http://www.amazon.com/Freeing-Your-Child-Anxiety-Practical/dp/0767914929/ref=pd_sim_b_4

This is a good book for kids. http://www.amazon.com/What-When-You-Dread-Your/dp/1433803186/ref=pd_sim_b_5