I'm going to respectfully request that this conversation stay ENFP only. I'm looking for thought processes on ENFPs and their derivatives without outside influence.
Assertion: It's impossible for an ENFP to gain self-confidence. All confidence comes from outside appreciation of any skill or talent we have built. Without outside appreciation anything we think, feel, create, or destroy is dross.
Now, once we have that confidence granted by another whom we trust, respect, or greatly appreciate, it does become integrated into ourselves. I would say that very rarely, once we are granted this confidence from another, do we kill it ourselves. However, someone else whom we trust, respect, or greatly appreciate... especially if we're involved romantically, has the power to remove these confidences from us as well.