How do I deal with this frustration?

I'm going to have to skip over a few parts and for the sake of length some parts will seem insensitive although they're not, but heres the story... I cheated on my girlfriend while very, VERY drunk. The worst kind of cheating, so in case no one knows: sex. I couldn't hold it in, and came clean with her after 2 days. She is taking summer courses and is several states away from me. I sent her flowers the next day by finding a flower shop near by and paying over the phone, and have bought plane tickets to go down and visit her this Sunday. I really love this girl. HOWEVER. I know I am in no position to be critical or be questioning any of her decisions, but she has been talking to her ex.. or in her defense, "best friend".. regardless, she has been talking to him about us, and he has obviously been telling her every little thing she wants to hear..she has said things over fb like "love you, miss you" and "you make me smile" etc.. on top of all this, (arguably deserved I know) she has been vague with texting, and emotionless..all of this would be more than reasonable IF she had NOT told me she is giving me a second chance..and is calling me her boyfriend again..soooo..very frustrating to hear her say that and then just blow me off like this...meanwhile shes going out to bars with friends including guys, and I haven't touched alcohol since my mistake because I can't handle it. Advice is much needed..thanks!