Teammates? Like a soccer team or something? You could've brought that up...
Emails, to me, aren't much different than phones or in person. I can just talk about 5 things at once, which makes it a lot easier for them to feel a wide range of emotions.
I've sent worse things on Facebook, I think. I can't be too sure because I don't have Facebook anymore. But I said some pretty lame things.
To save yourself you could say (I learned this from David D,), "What? Playing hard to get already? Talk to me". You don't need to put the "already" thing there because you already kind of know her. Up to you.
And I don't have the problem of girls not responding to emails too often, unless I'm responding to ads on craigslist or something, where those girls have their pick of 60 different desperate guys. I wouldn't ever meet a craigslist girl, though, because they'll figure out I'm lying about my age (15) eventually. I only test out email openers on them to see how they respond.
So far, I've had 3/10 -ish respond, and my results from those were very nice. One was really exceptional.
There was also a poll taken where the majority of women would give up sex instead of giving up internet. The guys had the opposite results.

But this means that you could give them both.

Well... If you know how, that is!
To get over that feeling, well... I'd just start feeling awesome about myself, and start working on inner game. You've probably learned from this experience, so you should just try again. And maybe on somebody else.