In all honesty, i haven't offered any real advice, but i went through a similiar situation. It sucks so god damn hard and I know EXACTLY the pain your going through. The nausea, the burning in your chest when you think about it, the hatred and wanting to

ing slit the guys throat. I know exactly how I felt afterwards. My only advice and it's the HARDEST thing to do is kill her with kindness and support. If you did truly love her, be happy for her that she found someone else. Sound sincere and tell her
"you know what i'm happy that you find someone you like so much, I wish it could have been us together but everything happens for a reason. So i wish the best of luck to the two of you."
I know this sounds crazy and you might be thinking (

that i'm not happy for them or this bitch). Even if you dont think this tell it to her sincerely. Let her go, thats what I had to do and long story short she was calling me 3 months later when he

ED some other chick and she was on her ass. I let her feel that way for about 3 weeks than i talked to her finally. Anger only fuels the situation to get worse. Kindness makes you seem humble and like theres no big deal. The way you have to think of it is this way mooky. There are 3 woman for every 1 man in the U.S. There are PLENTY of fish in the sea (i know you won't think this yet cause you want your fish, but hindsight is 20/20) and there are women out there who dont cheat. I ended up finding one and I plan on asking her to marry me soon.
Also as far as patching things up with her. Dont. Plain and simple. It might seem great for a while cause you overcame this big hurdle, but usually once a cheater, always a cheater. Plus you'll be happy at first and thinking (ya ya yay!) than about 3 months down the line you'll start questioning EVERYTHING she does. Where does she go to eat. When she goes out with the ladies, is it really the ladies? The way i looked at it is, why am i trying to patch things up with a girl who cheated on me and trying to make things work? Why dont i go find a girl who didn't betray my trust and not have to worry about what she is doing? When there are so many single woman out there, why would you want a girl who you will end up worrying about and not being able to trust? Dont hang out at bars either, thats just silly. Thats stupid advice and it doesn't matter if Mr. anderson is in high school or not, but at 16 your mindset is alot different than 24. Bars=pathetic men. Go hang out with your guy friends and try your hardest NOT to let this bother you. Again hindsight is always 20/20, i'm just telling you what i SHOULD have done when it happened to me, but now i have the chance to persuade you and hopefully help you overcome this quicker.
My final advice is to let her go.
Plus i can't believe shes moving in with this guy (is that why shes moving out)?
This has disaster written all over it man, she will fall flat on her face. I promise you she will. God has a funny way of making things come full circle.
oh and NEVER date a chick who is cheating on her BF to talk to you. That immdediately = slut. I'm suprised you lasted as long as you did. Usually those girls get bored of the guy they're with and

around behind the back to try something new. AND DONT LET HER KEEP YOU HANGING ON A ROPE BY TELLING YOU SHE WANTS YOU BUT CAN'T BE WITH YOU. I fell for that at first, she'll keep you hanging on JUST IN CASE this new guy doesn't work out that way she has her pillow to land on when she falls on her ass. TAKE THAT PILLOW away man, dont let her keep you dangling. GO out talk to girls, avoid nasty bars, and get crunk.
PS after you tell her how happy you are for her, wait like a week or 2 weeks and say you met someone, OMG it is the BEST feeling ever because shes not upset cause she's thinking your hanging on, until you meet someone to help you forget. Also take advantage of the rebound relationship if you can find one. Those help a ton too!