Well slow talk isnt really about talking slow. Its more about remaining calm while talking and not rushing your words out. Many of us when were anxious tend to talk fast because of the fear and racy thoughts we are experiencing. Slow talk(calm talk) needs to be learned by yourself until becomes automatic. Then starting with the easiest person you practice it until you feel little or no anxiety.
As you get further into the series you will learn that using absolute words like can't, never, always, and never must be eliminated. These words trick your brain into not being able to do those things you are describing. What you tell yourself your brain believes.
Also try to focus on what the other person is saying when they are talking. Then it will be easier to respond to them. You main objective is to be as calm as possible when talking to people and focusing externally. Its not a life or death situation no matter the outcome.
It looks like your still early in the therapy so much of what I said is coming up. So be patient about this as you will be learning many more strategies and concepts.