First, don’t tell me that the answer is just to “not bottle things up”, because that’s objectively incorrect too. Society doesn’t want you to have any negative emotions. I need to know how to not express negative emotions at all whatsoever unless I’m alone. I know it can be done because it is done in many other people on the planet.
There’s nothing corny about stoicism, as long as you see through the people trying to monetise it.