Meditation can help you to become calmer and provide you with a more balanced, chilled-out view of life. It can help you to be less agitated, less excitable, and enable you to cope much better with the challenges that come your way.
I recommend meditating on a regular basis. To start, play some soothing music, light a candle, burn some essential oils and create a nice place to be. Now I find that I only need to play the music that I use for my meditation classes and it calms me straightaway! Lighting a candle has the same effect. So, maybe that's what you can do initially to help calm you.