Sex isn't bad
I've had sex probably more than a thousand times, does that make my vagina loose? NO.
Just because a woman has had more sex than you and is fine with taking charge of her sexuality doesn't make her less, it makes her more. She is obviously fine doing what she wants with her body, sex is NOT a bad or wrong thing, there is no reason to have to be a virgin for a specific person, what is the point of that? I honestly don't see one. Until you want to have a baby, sex is purely for pleasure and there is nothing wrong with taking part in it. Just because your girlfriend isn't a virgin and your are doesn't make her a bad or dirty person. The fact that young men seem to sometimes think that because a woman/young woman has had sex that she is somehow not worth as much is bullshit. Get over your ancient viewpoints.
You should be happy that she actually has experience, that way if you do actually love her and keep your wits about you and stay with her, and eventually have sex with her, she can show you what to do. It will be better that way, believe me. Also, the fact that she has had sex 17 or more times is irrelevant. When you are dating someone, you don't count how many times you fuck, you just do. It is a normal and natural thing to do. I honestly hope you are like 14 because if I am talking to a 20 something I'm gonna pull my hair out. I hope other people have set you straight as well. Good luck. Don't leave a girl b/c she has fucked and you haven't, if you do, you're not very smart.
The End.