My DS6 (also almost 7) has been slowly working through some emotion control issues. I think he gets into little anxiety loops where he is embarassed by his own reactions and that makes it even harder. As he tries to assert control he usually needs a little space before he is ready.
I try humor sometimes which will help him break-through to rational thought. Recently, when he needs a little space, he's started saying between tears:
"please leave a message, beeeeep..."
There are theories out there about laughter erasing some of the long-term effect of big emotions.
When he's settled, I try to talk with him about the trigger. And if he is receptive I'll ask him to rate the tragedy of the event from 1 (not actually so important) to 10 (the world is ending tomorrow.)
In my mind the goal is to get him to stick his brain in between an event and his reaction. The emotional extreme may not be his completely to control, but the path there and the value he places on it could be.
