Jean1106

I (22 M) was out last night at the bar and I saw my ex-girlfriend (22F) making out with a guy at the bar. What I am very confused about was the fact that she said she wanted to get back together at some point. She told me the reason if anything did not work out between us would not be because of another guy, but solely between us. I feel very devastated and alone at this moment. I have not been able to sleep much at all since last night and this is all that is on my mind. Any advice ?