Overcoming this dragon will take great mental clarity and focus. The journey into the dark night of the soul is not for the faint of heart. And while most of us have to go through this painful life transition, it is how we think about our journey that determines how we will come out on the other side.
My spirit guide and I had it out many times over the power of forgiveness as I could not see how allowing someone that had done so much harm should be let off the hook. Letting them "off the hook" is exactly what we should do to free ourselves from the energetic (and sometimes karmic) ties we have created with our abusers.
Let's start with the basics. Energy vampires are usually lower vibrating individuals who feed off the life force energy of higher vibrating people. This is sometimes being done on a conscious level but often times it's unconscious. On a spiritual level, they are likely souls contracted to come here and force you (the empath) into learning to love yourself. After all, that is what most empaths are here to learn; love of self. I like to call them the teachers in the negative space.