I know nothing about relationships that's worth sharing but what I can say is don't take it back. You are devaluing your emotions and, even if you went overboard in stating them (and I'm not saying you did) you still should be able to be honest about your emotions. Maybe you can make a game plan of how you will discuss the email with her, actually write it out so you make sure you get to say the things that you truly feel and be able to talk about it in a less emotional way and a more productive, constructive manner?

Good luck,
Seesaw