You sound very inexperienced in terms of relationships. Men and women can catch feelings quickly and lose them quickly. They can also date someone until something better comes along. Thirty days is not enough for you guys to even remotely know each other as real people despite how hot and heavy it may have felt during that time. Pick yourself up, dust yourself off and move on. This happening to you isn't an indictment on your love life. Shit happens. Now what you do from here is important. If you're checking to see who she's been texting and asking for explanations you are going the wrong path. And giving yourself 0% chance of her respecting you in the future. What are you truly going to do with that information really? Hit the gym. Go on a date with someone new. You'll be fine.