I just returned from two years work on myself (learning to attract and succeed with women) and also learning how to be a man. There has been a major shift since then and I plan to post on this board about my experiences soon.
I came back to this board after and long absense. Fenderules, your post was the first I have come to.
Two things (offered with respect and hope you'll consider them) -
I'm not sorry for you.
An Italian proverb reads "The promises of a beautiful woman are written in the sand." - In other words, never COUNT on a woman.
Don't get me wrong, I love women. They are a pleasure. But, just like a musical instrument, you have to play them. (And I don't mean cheat or abuse them in anyway.)
This girl simply ceased to be attracted to you.
If she f***ked a band member at a show, it's because he attracted her through social proof and the EXCITING aspect of being with him. - Causing her to act against logic and acceptable behavior. (A woman is hard wired to be attracted to certain things.)
She did what she is programmed to do. She went for the ALPHA. (- I know this is hard to read)
Let's look at the breakdown of the musician/groupie dynamic.
Traveling Musician: Is the center of attention.. Is considered "cool"..Will be gone tomorrow..Is confident..
Groupie(or any female fan with realized sexual interest): Craves being the center of attention..Craves being "cool"..(this next could differ)Either wants to female social proof of being "mated" to the musician (thus serial groupies) or that one in particular (wanting to mate with the ALPHA of her group.)
So while this guy was being cheered and applauded on stage, being inundated with fans, making money, and f***king your gf, you were looking for her..and then warming up the car?
The ALPHA gets the girl, the praise, and the money while the BETA is servant.
Now, as harsh as that last section sounds, what can you do about it now?
The ALPHA makes decisions when everyone else is just following along.
If you haven't yet, get your stuff from her place (or hers out of yours)..DO THIS NOW!
2nd..Cut her out of your life..RIGHT NOW! (Tell her that she is no longer in your life.. Tell her that you will not listen to or not read any messages from her from here on out..and DON'T). Don't call her..don't accept calls from her or her friends..AT ALL! - Talk about changing the dynamic!!
3rd..Realize that you are worthy of other women's attention. Not only women, but hot women. Women who won't do this to you.. because, do you honestly want a girl who isn't excited by you, anyway? I wouldn't even waste the time.
4th..Enjoy yourself..this girl gave you a couple of gifts. You learning from this experience (and using it for good) is a gift. Also, you know what not to do.
Women are FANTASTIC. Have fun finding the one you want..all the others can go on thier way..
Go for quality women. Make them prove it..just like you have to prove it to them.
At the end of all the "That sucks, man" and advice replies (like this one), the only worthwhile question will be "What next?" Why not ask it, answer it and begin NOW?
Best of luck mate.