Blow off steam = to do or say something that helps you to get rid of strong feelings or energy (Cambridge dictionary)
I think the expression is an appropriate translation for the context.

Initially I thought ‘to vent one’s feelings’ may be an option but I don’t think it suitable because it implies expressing an emotion in a “forceful” way, which doesn't seem to suit your context.



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Note added at 13 hrs (2022-11-22 05:09:05 GMT)
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'نفضفض' معناها التحدث مع صديق عن ما يشغل البال من قلق أو حزن أو أوجاع…
على أمل التخفيف من تلك المشاعر
Blow off steam refers to the same thing. Blowing off steam can be verbally (e.g. talking to a friend, such as the case here), or physically, such as doing exercise.