My husband has this same stress trigger. In some ways it's a total blessing. Stess causes all kinds of health issues that can affect life span. So in some ways, my husband's MS is like a crazy alarm bell for when he's doing something stupid, like letting himself get worked up. (Clearly he would have chosen a different kind of alarm bell if he could have, but hey.)
For my husband it's about prevention. It takes time to come down from stress, period. So it really is about not letting yourself get worked up in the first place.
Can you try a 5-minute morning meditation? Just a few minutes of sitting quietly, reminding yourself that the world is basically a kind and beautiful place. That bad things happen, but we control our emotional response to those things. Calm, calm, calm...
I read a book by Howard Cutler and the Dalai Lama a while back, called The Art of Happiness. I'm not a Buddhist, and this book wasn't written for Buddhists. It was written for the average American, and it talks about ways to live a happy and balanced life. It's a little touchy-feely, but so is the whole stress-reduction gig. Overall, it had a lot of good ideas in it. Check it out.
Good luck.
Mamacita