I really don't understand that. The first isn't a big thing, especially if it doesn't work out. How about instead of dwelling over the fact you aren't first you instead make sure you're the last? That's a million times better and means a hell of a lot more.
I would prefer to not help you get over the agony of not being the first guy to deflower this particular girl. In North American societies, women are respected largely for what they've accomplished, versus on how 'pure'/'impure' they are.
um ok so she had a love at 14 and 15 years old how old was she when you two started dating? and you best learn how to get over it because most people you will be with will have most likely at least been in one serious relationship before you came along.