I totally understand your situation as I am a language learner as well.
I always believe that a talkative person learns the language faster than a shy person. ( Actually I am the latter one. ^^;;;)
And also you don't need to feel shy to use other language(Korean or other languages).
It is Not your mother tongue.
Here many people will help you! Don't worry to make a mistake!
We are here for you!! lol