Knowing all of this is only part of the solution. How do you know if and when to say goodbye? A key to this is identifying how long the relationship has felt unsatisfying, how much effort you and the other person have put into resolving the issues in the relationship and how it is impacting your life. When you no longer look forward to spending time with them, find that the unhappiness in the relationship is bleeding into the rest of your life and you or the other person is either unwilling or unable to put effort into improving the relationship, it is probably time to walk away.
While a few drinks with girlfriends may make you feel better for the night, you're sure to feel worse the next day — and not just from a hangover, but wondering why (OMG why?!) you told the bartender about the STD your ex gave you, why you kissed that guy in the parking lot and how you got home.