First, don’t tell me that the answer is just to “not bottle things up”, because that’s objectively incorrect too.

Well, no, it's not objectively incorrect. I get the sense that the main problem you have is communicating negative emotions without being overly confrontational or acerbic about it. My experience is that it's very possible to tell someone you're unhappy about something without making a major deal out of it.

Also, I'm curious about how often you find yourself in the situation we're taking about. Everybody had occasions where they have to vent frustrating, but if that's a super frequency occurrence, there might be something else going on. Sometimes it should be enough to take a deep breath, recognize that the issue is minor, and let it go.

This reminds me of something a European told me about dating in the US. "Americans say nothing is wrong and then blow up when it's a level 11 problem and i had no idea anything was wrong. Where I'm from we address it when it's a level 2 problem."

Be a level 2 problem, not a level 11 problem. That means you gotta fucking talk.

don't tell me that the answer is just to "not bottle things up"

I hate to be that guy, and believe me I was in that boat once. But the solution is to not reach the point where you are exploding from the amount bottled up.

Humans are not meant to be stoic creatures. People have feelings, that's called being human. You need to find someone you can trust(NOT A COWORKER), and every once and awhile vent to them about things that you aren't able to resolve with the person that's causing the frustration. That's your best solution.

Reading your replies, this seems to be more a super toxic work environment issue which I think if you fix, will resolve most of your issues. Due to this, I recommend ON-TOP of the previous recommendation, also either contacting HR about it, or if you do not feel comfortable with doing that, finding another job. You should not be being bullied by anyone let alone a manager. There are so many work policies in place in most work environments protecting you against this, and not to mention most civilized countries have laws against it.

Being said, if you feel that it is less of a you bottle things up, and more of a you aren't thick skinned enough to be able to handle the every day work-life without having anger issues and exploding, you may also want to look into some form of Anger management or calming technique. But honestly, it sounds like it's a combination of the first two issues and less of an anger issue.

It's corny and is championed by some shit heads but Meditations by Marcus Aurelius helped me to figure out how mentally center myself during tribulations.

Link to Internet Archive

1. You need to voice your concerns when they actually come up. The idea that showing emotions is objectively bad is completely false.
2. You need to learn how to phrase negative comments with a neutral tone. You should not be describing anyone as mean, rude, bitch. Especially not your coworkers. Do you mean straightforward? Concerned? Talkative? Direct? Extroverted? Confident?

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'm guessing you're a man. Society imposes this upon men in particular.

Tell society to fuck off. Have emotions, experience emotions, and process them like a human being.

Then take it a step further, and learn how to handle them like an emotionally intelligent human being.

I need to know how to not express negative emotions at all whatsoever unless I'm alone.

This is part of the problem. This is not what you need to know. You need to know how to express negative emotions without losing control of yourself or your reaction to your emotions.

I know it can be done because it is done in many other people on the planet.

People bottling things up and exploding when in a safe space is part of the problem.

I'll echo the idea of anger management, or even therapy in general.

Nobody who is healthy hides away their emotions. You're not alone in feeling the way you do. Society is sending you signals that you need to do something unhealthy, but that won't actually fix the problem.

This is a question for a therapist. So my answer is, whenever you have an open mind to the idea of being uncomfortable in order to grow, start researching therapists.

So you harbor resentment.

Clear the air, don't take things personally, realize other people's emotions are out of your control and move on with life.

Easier said than done, though.

One of the most healthy practices you can do is to fully experience negative emotion, let it wash over you and fully occupy you, then breathe deeply and let that emotion go. Holding on to negative emotion has long term health consequences. Remember that you have no control over the world, just your own reactions to the world. I have a lot of anger that I try to let go of this way. Life has become a long series of just being shit on by everyone and everything. But what can I really do about it? Keep working and moving up the ladder to where the shit sandwiches have more bread I guess. In the meantime, I try to practice mindfulness with my emotions and breathe through them. You can use the Dune Litany Against Fear with pretty much any negative emotion.

I think it’s more of finding ways to express negative emotions in a healthier/safer way, and not necessarily just suppressing it.

I recently took an anger management class. That might be a good place to start for you. One of the takeaways I got was that it's ok to have anger, but you need to learn and use different techniques for managing it.

1. Set and enforce boundaries with everybody in general and specifically for people you feel overstep. Basically either faux-pas or actively try to fuck with or trespass you in any way
2. Grey rock people who you believe are antagonising you

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.

What about your friends or family? Particularly in some countries, it's true that public displays of unhappiness are taboo. Less-than-totally-public displays are kind of a huge part of people's social lives everywhere.

Got to therapy. Seriously

Don’t bottle things up.

Take a lesson from welding class: You release what you've got bottled up just right with a little spark and you get an intense yet precise flame. It's amazing what you can get done with skillful application of said flame.

Journal. Let your feelings out, incrementally, in a place that you don't feel vulnerable for doing so.

Today co-worker did X, they're a cunt. It annoys me because Y. Seriously, Co-worker is a dick. At the time I wish I had done Z, but Z is illegal. Nexr time I'll try [reasonable action]

Nice people tend to let things go, they will eventually catch up and you will blow. Instead when something happens or something is said you need to stand up right in that moment. This way it was dealt with and there is nothing to bottle up.

I would say therapy and find a healthy way to offload steam such as exercise or meditation or walking your dog or hitting a few balls at the driving range...etc you get the idea.

Regarding therapy, if you want to explore that it may take a few tries to find someone you click with but I have many friends who swear by it and say it was one of the best things they have done.

I would suggest that you try to process those swallowed emotions at a later time. Ask yourself why these things bother you, can you let them go, do you need an outlet to relieve them. Maybe you can relieve that pressure before you blow.

Some dark humor helps.

The people commenting on here are unhinged. Clearly a lot of "I was treated poorly by my boss so you should deal with it too" energy.

I saw someone imply it couldn't be bad unless you were being physically threatened with a knife at work. Ive seen people say you should just say how you feel when you feel it, but that won't change the main problem here which is that its not okay for a supervisor to treat people poorly.

Nothing you change about yourself will change your supervisor. People quit managers not jobs, in most cases. It wouldnt be unreasonable to look for other work or to request a change in supervisor/team.