Here are my great soothing relaxation techniques, that I have been using to cope with my pregnancy worries (and contractions), but they work for everyone's life, especially as a mom (like when the baby's on a crying marathon). First of all, Yoga's a fabulous de-stresser, if you have time to take a class... Do it (plus it can help you learn how to focus on breathing).
But my primary technique, breathing, you can use just about anywhere, anytime, to soothe your soul. Sit with your eyes closed and imagine a beautiful, peaceful scene (a sunset over your favorite beach; a serene mountain vista). Then, working your way up from your toes to your face, concentrate on relaxing every muscle, one at a time. Breathe slowly, deeply, only through your nose and choose a simple word (such as "yes", "positive", "gratitude", or "one") or mantra/affirmation to repeat aloud every time you exhale. If you are concerned with others hearing you, say your word in your head. Sometimes, I also count as I inhale and exhale, 1-2-3-4-5-6, I allow my breath to get longer and longer. Ten minutes should do the trick, though even a minute or two is better than nothing. De-stress your stress, no matter who you are or where you are!