impossible jobs

This afternoon, my superior said to me.
"You should participate in an international meeting! It is sure to become a wonderful experience for you."
"I am not confident of speaking English."
"Your English won't improve unless you join in the conversation without being embarrassed."
"・・・・"
I want to participate in an international meeting.
But I get a painful sense of the inadequacy of my English vocabulary when I talk with a native speaker.
Persistence pays off. That's how it is with English. Working hard every day is very important.
I should speak English more often and enthusiastically. I don't care if it's not that good yet.