Can't Get My Mind off of Someone?

I was with a girl for about a month, and we never really got heavily into a relationship, but I got a bit jealous of how close she got to other guys and she broke it off. I can't stop thinking about her and I don't know how to get rid of the feelings. I know pleading to get back together would be a bad thing, but even my old stress-relievers, running and listening to music don't even clear my mind of her. I need to get her off my mind because its been eating at me ever since we broke up, but I don't know how. I'd appreciate suggestions on how to get rid of the feelings or how to get her back.