I don't get how a guy who gets 7 notches in the 3 months that he was "dating" this chick, is getting all upset and catching oneitis. I'm not a super alpha player like a lot of the guys on the forum, but to me 7 notches in 3 months is a good bit, enough for a guy to not give a fuck about a particular girl. Also 3 months of dating is just scratching the surface of a relationship, 3 months is when you are still in the honeymoon phase and when things kind of slide from just dating to a relationship.
My guess is the O.P. has a fragile ego and is tripping over this chick "choosing" another guy, that or maybe he's a real good looking dude whose been getting chicks on easy street and is not used to rejection. Either way you been notching your belt with 7 other chicks while you been dating this one girl, then you really shouldn't be too upset, in my opinion a guy fucking that many other chicks wasn't very serious about his girl or the relationship to begin with. You can't get mad at her for being real and upfront with you, I seriously doubt your were real and upfront with her.
My guess is the O.P. has a fragile ego and is tripping over this chick "choosing" another guy, that or maybe he's a real good looking dude whose been getting chicks on easy street and is not used to rejection. Either way you been notching your belt with 7 other chicks while you been dating this one girl, then you really shouldn't be too upset, in my opinion a guy fucking that many other chicks wasn't very serious about his girl or the relationship to begin with. You can't get mad at her for being real and upfront with you, I seriously doubt your were real and upfront with her.