Wow. It has been over 4 years. I had nearly forgotten about this post, but I'm sure some random internet lurkers are bound to happen upon this thread and want advice about their own situation or just want to know how things turned out. First of all, thank you all for the advice. To all the lurkers, there is some awesome advice here.
I married her! Never regretted it! We're loving life. Now, a few things that I've learned:
1. She was never the problem. It was always me (basically, I was an idiot).
2. The idea of virginity is just that, an idea.
3. What matters most is that you're best friends. Best friends are loyal to each other no matter what happened in the past.
4. The past isn't real. The present is everything. The future is a dream.
My advice, is that if you're in this type of situation, get over yourself. Assuming your significant other is completely loyal to you, if you still find yourself "haunted" by their past then the most important thing you need to ask yourself is, "Can I be the spouse my SO needs?" If the answer is no, then stop jeopardizing your SO's happiness by constantly dragging your thoughts through the nonexistant past. Get out of the relationship for their sake. If you can honestly answer yes, then go for it. You've got an entire lifetime to make amazing memories together.
I was taught growing up that it was better to die than to lose your virtue. I disagree with that. I was also taught that those who had lost their virtue were like "licked ice cream" or "chewed gum". That way of thinking is wrong, and it's very harmful. Let go of that type of thinking. It benefits no one.
Elizabeth Smart talked about what it feels like to be a "chewed piece of gum" and it sounds terrible: http://fox13now.com/2013/05/06/elizabeth-smart-i-felt-like-a-chewed-up-piece-of-gum/ Don't put your SO through that. If you're best friends, nothing else matters.
Best of luck to your SO (and you) if you're in the situation I was in. In conclusion, this image sums it all up: