So, here's the thing. You need to make an important sale. Is the best way to prepare for it to get more angry? Is quitting your job without having another lined up what you'd consider a winning move?

There are times where being angry actually helps, but they're a lot less common in the modern world. Usually, it will screw you over. (For example, getting angry in traffic is utterly useless.) Starting that argument because you're angry makes it unlikely that you'll actually persuade anyone.

You'll make a better case if you're calm about it and can think clearly. How do you do that? Meditation is one way.