Why do I feel that I've just made a huge, HUGE mistake?

I was awoken this morning [well, it was 9:30am...] by a phonecall from the Principal of Bryant Elementary School [where I did my Student Teaching]. He first asked if I had heard anything about getting on the Substitute list [um, this was supposed to be something that HE would keep ME informed about...], and then asked if I would be interested in a long-term sub position in the 4/5 split class. I pondered, and waffled, and stuttered, and probably came off as completely unprofessional. Then I told him that I wouldn't be able to teach on Tuesdays because I have class - which is the truth - although, TODAY is Tuesday so he must have been thinking, "Um, well then why aren't you in class right NOW??!!" He made it seem, though, that he'd be willing to work around the Tuesday obstacle. And then I said that I wouldn't feel 100% comfortable in a 4/5 split because my credential is an Early Childhood Emphasis Credential - meaning that I am most qualified for Pre-K through 3rd grade. And, honestly, I really have no experience [or INTEREST] in teaching any grade above 2nd [I didn't mention the "interest" part to the Principal]. It would be like having the team catcher be the pitcher for the World Series [well, ok, that is a bit emphatic...].

Oh, and to make things WORSE, when I mentioned the "not really feeling qualified to teach upper grades", I said to the Principal, "And I JUST had a dream about teaching Kindergarten..." HUH!? Am I an IDIOT!? Why would I tell that him that I JUST woke up at 9:30AM on a TUESDAY!?!

UGH.

SO, I feel like I've just TOTALLY BLOWN my shot at getting Miles's job next year. I can just see Miles saying [I'm going to call him later today], "WHAT were you thinking?!?" And I can hear the Principal saying, "Well, you weren't willing to step in when I needed you, so why should I hire you now??"

CRAP!