Why must my heartbeat so quickly - and I can feel it - that makes me so anxious in difficult, confrontational meetings? In the last few days I've had these experiences and in both, I'm stumbled and quivered my words out probably leaving my subject either confused or in my work environment, thinking "he doesn't know what he's talking about". I have no idea how to make my inner body be calm so at least it's not making my heart beat that I can think it may just come out of my chest!
Before the meeting, try to put your ideas in order so that they come out more easily.
Make clear, short sentences and write them down. Try to memorize them.
Take slow, deep breath to calm yourself down before going to your meeting. Try to put yourself in the mindset that today, you're the most easy going person in the world.
Keep breathing slow and deep as you go to your meeting, and bring your piece of paper.
Keep breathing slow and deep during the meeting.
Don't look the person in the eyes when you speak if it makes you lose your calm and forget your ideas. You can look at them when you're done speaking or when you say the last words of your sentence.
Don't waste your energy trying to cut people while they are speaking, unless really necessary. Just wait for your turn, and keep breathing slow and deep while you listen.
When they finally shut up, say your clear, short sentences. Try to speak clearly and not too fast. Look at your paper if needed. It might look odd, but who cares.
For anything that is not on your paper, take your time to think and breathe before answering, even if the person in front of you look impatient.
That's all I got for now. It's been working well enough for me.