I just want to know what to do?

my girlfriend who recently broke up with me said it was a break and we would get back together soon i clung to this hope because i love her so much but she told me today that she had been seeing and getting to know a guy to take her mind off me and he was only a friend and not worry because she still wants me back. it has only been a little over a week and she is already meeting new people after a 2 year relationship. i want her back so bad but should i cling to the hope that nothing will come of this guy and we will get back together or just give up completely. the guy she is talking to lives in iowa we live in illinois and hes leaving in about a month and she claims she doesnt want long distance relationships