Here's the thing.
You can validate someone's anger, but, it's harder when you want to validate your own anger. Especially when people don't acknowledge your anger and even make fun of your anger as if anger is joke. Especially when the people making fun about your anger hate you for making fun of their anger.
Anger is not a joke. Anger is the most valid feeling a human can have. And curse anyone who ever made fun of anyone's anger.