Why can't I just shut my mouth.

Why can't I just shut my mouth. I'm always talking, talking, talking. It's not that I tell secrets that I am meant to keep. All I do is keep telling too many details, telling too much truth. I am in discussions at work about turning my contract into a permanent position. Is it wrong if I am just interested in extending my contract?

How do I tell them this?

I can't tell them the following truths:
* I don't fit into their business
* There is no place for me
* I have been given promises and they never came to fruition
* I am bored and can't see the challenge change
* I don't agree with the direction of the business
* I can't wait until the project is finished so that I can move onto the next one
* There is nothing new for me to learn
* The business is !@#$ed

I probably should I tell them:
* That I want to see the project through to completion, but when that happens I'm not sure what I want to do.

Hmmm. Any suggestions would be appreciated.