What should I do.? Please help.?

Okay, so me and my ex girlfriend were going out for a year before we decided to break up. The reason was because we fought and argued way to much than what was necessary. Well after we remained sort of I don't know, friends with benefits? More than that, We still met on a daily basis, kissed, told each other we loved each other, things you would do in a relationship. The only thing was she would talk to so many guys, and go to the movies with other guys. She's told me time and time again that she doesn't do anything, like I think she is. I told her the day I find out she's doing something with another guy I want nothing to do with her. The thing is though we're not together so she flirts with so many guys and things like that, but in the end it's basically like we're together. She comes with me and my family to places and that sort of things. Well yesterday she came over and signed into Facebook with my iPod and she fell asleep and remained signed in. So I decided to be nosy and look at her messages, I came upon a message that was her telling her cousin she made out with some guy and blah blah and talking about other guys. And another message talking to some guy saying she'd send him a picture of her stomach. I woke her up took her home, confronted her about it saying like why are you being so easy telling this guy you'd send him a picture and blah blah, she replied by saying that's not being easy. I then said bye and left home, then when I got home is when I saw the message about her making out with the guy and all those other things so I texted her told her what I saw and told her I want nothing to do with her, and for her not to talk to me and I said bye. She replied by saying she didnt do it and all this other bullcrap sent me like 7 messages saying like please!!, reply!!, Babe!! stuff like that and her last message said I'll always love you and i'll always be here for you call me whenever you want to talk..byee.. and I never replied. Is this the right reaction? Should I not be mad since we're not together? Although I feel as if we are. I still love her very much, and I don't know what to do. This hurt me very much. Sorry for it being so long, What should I do????? please help. Thanks..