Nah not at all, none of us are as eloquent when talking as we are online. You have so much more time to think when typing a post, you can go back and edit, delete stuff you were about to say etc. Its one of the reasons we are all here. Besides all that, listening is important too - people like to talk about what they are proud of.
Grab someone of the forum to skype with and practice if you are very worried. Everyone here has thier own issues and wont think any less of you.