Instead of falling into the rumination that inevitably comes with venting, leading mental health charity Mind recommend almost doing the exact opposite, saying: “Relax your body. If you can feel your body getting tense, try focusing on each part of your body in turn to tense and then relax your muscles.”
Article source: https://www.huffingtonpost.co.uk/entry/is-venting-healthy_uk_6998332be4b0ab1f9f454ebc