Long distance relationships "are" tough, it takes a lot of commitment and love to remain in it.
She could feel emotional, lonley. Stop texting, pick up the phone, stop wondering and make her laugh, feel loved, just persue it as you would have when you met her. Sometimes text messages mean jack **** as communication especially being an hour or so away from each other.
Also when did you last get in your car and drive to her? It's not a huge distance and you need to make the effort as much as possible, both of you, to see each other as often as you can to make this work.
Another man/ woman for that matter will always come into someone life and try to get what they are after, only to then walk away after . Strong connection won't allow that to happen, so make your connection stronger than ever.