Is your mojo missing? A lackluster sex drive can be caused by many factors — some of which are more obvious than others. Are you working too hard? Is he the problem? Don’t panic; help is here. Forego the frustration and focus on finding the culprit instead. Identifying the problem is step one in reviving your inner sexy and getting back to the bedroom fun you miss. Here are 13 “mood killers” to look out for and how to reverse them.