Is This New Guy A rebound or Does she really want to have a relationship with him?

I've been with this girl for about year and the past 6 months leading up that year have been rocky. We love each other a lot but just been fighting and making up a lot. The last time I slept with her was about a week ago during our period of non-exclusiveness, and a week after that before her final she ended having with a friend of a friend they met up with at a bar. I know she was trying to relax at a bar before her exam, so she must have been pretty hammered to have slept with this guy she barely knows. This guy is nothing like me at all, and if anything a huge downgrade, but he may be an awesome guy I don't know, but its obvious why I would bash him. A mutual friend told me this and also told me two days after they hooked up they have been constantly texting non-stop and he lives about an hour away. I know its easy to say get rid of this tramp, but I love her and its hard to let someone go. Is this guy a rebound? or could this maybe be the real thing since they text non-stop all day and all night. Was she just still sleeping with me until something better came along? She said she loved me and always will during our rocky relationshipl, so maybe it is more than a rebound and she was just waiting for the right guy to come around. I have no idea, and its mind boggling to think after the week I slept with her she would do this. And if they are texting so much, and hardly know each other, could this be the real thing, and her move on without ever thinking about me again? I know I am backing off and haven't mentioned what I know to her, and I told her friend to stop telling me these things cause it doesn't help at all. I just want to know if I still have a chance to get her back or is she over me or just trying to figure things out and start something new with someone. It hurts but if it is I know I will let her go and wish them the best. Any input from thoughtful ladies out there, who would like to share their input on this situation, I want an honest answer, not the one I want to hear. Thanks :)