There's a really good Abraham interview on revenge, which I can't find just now. I'll post it later if I find it.
I suggest you go on youtube and look up some of the stuff on anger by abraham hicks. And if you're angry, well then someone being all like 'hey! fairy dust and waffles and sunshine!!' is probably just gonna piss you off. If you're angry, then BE ANGRY for a while. Yeah. Better than falling down into depression. What that girl did to you just sucked; cheating is a class A BITCH thing to do.
Yeah, I'm not saying STAY in anger. But I've been there, I know how much cheating hurts. Use that anger to get your power back. When you've done that, then take the advice of the guy above (Mike). He's got good advice, I just feel you might not be 'there' yet.
Use your anger, get back in touch with your personal power. When someone cheats on us it's cause deep down we don't hold ourself with the value and love that we should. So that anger is yourself saying NO! FUCK THIS SHIT, I DESERVE BETTER!
Damn right you do. And you can have it, too. Just climb up that emotional scale.
HUGS. And I'm sorry for your situation. Remember, you can climb out of it xx