Thanks for posting this topic. This is a topic where I also would like to learn more. I personally don't seem to have anything I remember that would clue me into a past life. But I do get occasional Deja vu moments that make me wonder. However, my wife is unnaturally afraid of drowning at sea and has never had a related water scare in this life. So we always joke that something bad must have happened in a past life where she drowned at sea. And your holocaust flash backs seem to point to a prior life event as well.
From what I understand about past lives from reading about it is that we all keep coming back to gain achievements so that we can elevate our soul. After we die we are given the opportunity to come back on another mission. If accepted we are told me have to make certain achievements and learn lessons in the next life. We then come back but don't normally remember what our purpose is or what we are supposed to learn or achieve. We come back with a clean slate and have to live our best life and hope to pass the tests and level up. At a certain point our soul has reached the highest level and we are given higher being options (becoming a spirit guide, angel etc....).
But since I admittedly don't know that much about this subject, I am sure we will hear from others shortly on how this all works and your connection with the holocaust.