Vulnerability is NOT oversharing.
Vulnerability is MUTUAL. That means the person with which you are sharing is also bearing her soul (maybe not in that exact moment, but sometime in the friendship).
Vulnerability is about sharing feelings and experiences with people who have EARNED the right to hear them. People who try to shame you, laud over you, tell you what to do, or fail to self-disclose, have not earned the right to hear your story.