Look, don't bomb her out of you life, that's chump talk.

What have you possibly got to gain from cutting her out of your life? Think selfishly for a while. What do you get from ending your friendship with her? Nothing.

You think that cutting her out will make it hurt less, guess what, not only will the pain linger for a long long time, but it will also be added to by this question "what if?". And believe me, thinking back about the first girl you loved, and not having the balls to tell here about it will haunt you for many years to come.

So, though your situation is a difficult one, and i do sympathies with you, but you've got two choices really. Prey the obsession go's away, or bite the bullet and tell her how you feel, before she gets a BF and its too late.

At least if you tell her, you have a chance at her, and if the shit hits the fan, you know you went out fighting, and wont wonder what could have been.