Dude, serious, your situation is exactly like mine. Exactly! The Love, the breakup, the NC, getting back, found out about a dude, dumping her! It is the same situation
Now you have two options.
The first one is do what I've done which is getting desperate and
chase her after some weeks, which will give her all of your power, and
will only cushion her fall and make her
absolutely sure about the breakup. This will make her
despise you, being indiferent to you and you will have a hard time trying to get some closure out of it. It has been
5 months now, and
I still cry EVERY SINGLE DAY. And I know that since I've chased her so much, she is not going to talk to me at all. Ever again. And this is what hurts the most. And if I want to have a decent chance to talk to her again, it is going to be in the Long Run. I mean 2 to 3 years run, so that she sees that I've stoped chasing and moved on with my life.
Or
Remain
no contact for at least 3 months, which
will drive her crazy, 'cause she
still have feelings for you, and after this 3 (long and painfull I advise) months, you will be certain if she is worth it or not. She will probably send you lots of messages, but if you remain no contact, she will respect you more in the long run, and will always, and when I say always I mean always, keep this feeling with her. Wheter you guys get back or not. Eventually she will say she does not want to get back, but just want to clear the air, to have some closure, but she will want you back the minute you snap your fingers.
Now it is up to you to decide which position do you want.
You want the upper hand, suffer for a while, and then get some decent closure, and always have her as a f**k buddy.
Or you want her to despise you, and keep you suffering for months (or even years) to come, without having the closure we all want, and not having her at you card list.
One thing that I can tell you for sure is, just like mine was, this guy she is with is just a rebound, she will compare him to you, and WILL be disapointed. So don't be affraid that you are losing her to him.
But aside from this, remember,
she did broke up with you to try another guy, so open your eyes for this. Once a cheater, always a cheater.
If she had the guts to do this once, and in a period you guys were so much in love,
don't go assuming that she won't do it again.
Check this link as the dude above said. You might find out some insightfull s**t about this "crazy" and out of the blue behavior of hers!
http://gettinbetter.com/anycost.html
Best of Luck man!
And on a personal note, if you choose the
first option, you are on for a terrible ride, of emotional pain, shame, guilt, fear and confusion. Besides the fact that you will be checking this page far more than you would have liked to.
I'm in day 14 of No Contact by the way. And it Sucks to be so early on, after so much time.