I don't know. Completely avoiding her seems like running away from what needs to be done.

Don't let her go. Let her know that you love her, that you'll be there whenever she needs you. Let her know what she really means to you. If she'd rather be with someone new than you, there's nothing you can do to change that. I've been there. There's no convincing a girl when you've become old or tiresome. But, maybe, if you show her just how much she means to you, she'll realize what a great guy she almost threw away.

But that solely rests on whether or not you are this guy. Be who you really are, and do what you need to.