What does it mean when you are told "don't be a martyr"?

don't intentionally victimize yourself. Someone who makes themself a martyr is typically looking for respect or pity for their selfless act. In fact, when the motivation for the action is attention rather than the better good, the action becomes selfish. The bible says that it is good to suffer, because it brings us closer to God, but that we should not intentionally make ourselves suffer because it's an act of vanity.