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.
Edit: Ok so I think one of the things I want to try doing next is ask for a med change from my psych provider.
There’s a lot of really good advice here, I’ll just pitch in one thing I’ve been working on myself lately: mindfulness. Awareness of yourself, your surroundings, and how you feel (both emotionally and physically).
I’ve struggled a lot with the same problem of bottling emotions up, but I often do it because I don’t even register all of the little emotional paper cuts that feed into it. It’s helped me to make it a habit of stopping and assessing myself and asking “hows does this make me feel and why?”
Start doing that for even the little things and you’ll find it gets progressively easier to stop and assess even the bigger things. Won’t always make you feel better, but oftentimes all we need to avoid blowing up is that second of “stop and think” to make us cool off just a bit.