The X again

So I sent my x a message on FB today and later asked my sis if that was a stupid thing to have done. She then informed me that he was already seeing someone else. Yeah it hurt a bit to know that it was that easy for him to move on, then again he did cheat on me so its not a complete surprise. I don't know what to think anymore, I'm not going to bug him about anything so I just messaged him back saying that I know he is now with someone else and that he should just disregard that last message. I know I hated how he cheated on me so I'm not going to give him the opportunity to cheat again on someone else. I'm just so tired of being alone and having horrible luck with guys. I'm sad and mad and just want to hate the world right now but it won't make me feel any better so I'm just going to let it all go and just not want any relationship. It does suck that I'm still in love with my x and still want to be with him even after all that he has done to me. Hopefully I can leave all this behind when I finish up my apprenticeship and move away from Texas.