If you are not already familiar with The Institute of Heartmath they have some amazing tools for anyone who needs a boost and better alignment with your heart and nervous system. Here is what they say about themselves.
Our mission is helping people reduce stress, self-regulate emotions and build energy and resilience for healthy, happy lives. HeartMath tools, technology and training teach people to rely on the intelligence of their hearts in concert with their minds at home, school, work and play.
They've done a ton of research related to stress reduction an emotions. One of the tools that you can utilize anytime is their Quick Coherence Technique for Adults which can be used anytime, anywhere. Here is the link to this specific exercise, but I suggest you check out the whole site. http://www.heartmath.org/free-services/tools-for-well-being/quick-coherence-adult.html?mtcCampaign=19055&mtcEmail=41291109