@Dface This is all replies to stuff that Max said, but it is meant to apply to your situation/problem.
I think “mastering” emotions may be the wrong way to think of them. It is hard to tell because it’s not really explained, so it could mean a lot of things. But usually when people talk about, say, mastering their anger, they mean that they still get angry, and they just have some amount of control over it. They are able to suppress it, or use it in a targeted way, instead of feeling overwhelmed by it.
So they aren’t really resolving the issues, beliefs, internal disagreements & coercion, etc that are causing their anger. Instead they are just channeling, controlling, suppressing, etc, the anger.
If someone doesn’t have a lot of experience paying attention to, understanding, changing, etc, their emotions, then a conversation with another person is not the best place to start.
It is better to first start paying attention to your thoughts, physical sensations, etc, when you are not emotional. You can learn to sort of step outside of your thoughts & feelings and view them on a more meta level when you are calm. Paying attention to thoughts & feelings like that is a skill, and it is easier to learn & practice this skill if you start while you are calm, and then later you can start to apply it when you are feeling emotional.
(This is what mindfulness meditation is: you learn the skill of focusing your attention, paying attention to your own thoughts and feelings, being able to view your thoughts and feelings from an outside perspective, etc)
Once you can use mindfulness, a lot of people will be able to use it during an emotional conversation with another person to calm themselves down, but in the beginning, usually the best thing for them to do is leave the conversation until they are calm. (There are exceptions when it is a conversation you have to have, like a decision needs to be made with another person.)
And people mostly should not be having conversations on here that they are emotional about – the conversation quality really suffers, people end up being more irrational, illogical, hostile, mean, etc, when they are emotional. So I definitely don’t think people should be having emotional discussions here as a way to practice dealing with their emotions. In general, people should not write messages on here when they are upset.
I agree the emotions essay has good advice. But to be able to follow that advice, I would suggest first practicing mindfulness meditation, to get some practice with the skill of paying attention to thoughts & feelings in that way.
Once you can do mindfulness meditation when calm, you can start to apply it to your negative emotions. One way to start is to think about something you are emotional about. You just bring it up in your own mind, when you are calm. You don’t need to involve another person, get into an argument or discussion, etc. You can instead think of something that upsets you and pay attention to those emotions.
This is a common type of guided meditation practice session: they will direct you to think of something that upsets you, and then pay attention to your feelings. The mindfulness meditation stuff directs you to just pay attention to your feelings. You can do that first, start to identify what you are actually feeling, what it feels like in your body, what your thoughts are, how you know you are upset, etc. And then when you get good at that, you can apply the emotions essay advice.
Then once you have practiced on your own (when you don’t have another person to worry about, or a current problem to deal with) you will be better able to use the same techniques in real time when emotional situations come up.
Of course, if problems come up in your real life before you have practiced much on your own, you can try to use the meditation and emotions essay advice to deal with them and calm down. But you shouldn’t be seeking out things that will make you emotional when you are just starting to learn these skills.