Jealousy sucks and it's hard to pin down which is why it's often called a "useless emotion."
Are you looking to understand the root cause of it, or motor through it? If so, physical activity and perspective is the way to go. If you want to stop it at it's source, it's usually the result of a serious insecurity about something. If you can nail down exactly what that is, you have a much better chance of squashing it or recognizing what's really going on in the future.