Bingo.
There's a lesson here for the both of you.
You: learn to accept the fact that the people you might be interested in may have had sex lives (even interesting ones) before you. You're entitled to feel how you feel, but sex is fun. Damn fun, and we as a society are becoming more open to the idea of exploring it. The idea that the person you're with has to be a virgin (or only experienced in vanilla sex) is a little naive, and this will become more true the older you get.
Her: Girl needs to learn to keep her business to herself. Nothing wrong with sharing with your significant other, but from the sounds of things, she dived right into the nitty gritty details, and it was way too soon for that. Don't get me wrong, ain't nothing wrong with a 2-for-1 dick down, but that CAN be a bit overwhelming to just drop in someone's lap.