^Be aware of the state of your emotions at all times. If you find your emotions taking hold of you, breath. Notice your breath and slow it down. Look up and out at something vast, like the outdoors. Breath slowly some more. Seeing an actual broad perspective with your eyes can help your mind make room for your emotions to spread out thin and evaporate.
A technique since ancient times is pondering God or the vastness of a deity. In newer times, many people will ponder the mysteries of Uncertainty at the Quantum level, or imagine their Actual Size in relation to the vastness of space and the fullness of Time.
Whatever technique you have at your disposal, make use of it. It lets you see your problems from great distance away and may help you unravel them, untangling the knotted Christmas lights in your mind.^