Well, when I had my second traumatic event, I didn't know that I had been re traumatized. But the symptoms of the shock were there. I experienced something which could have lead to another re-traumatization, but my therapist and psychiatrist quickly swooped in and prevented that, but I did get flare up again.
So, when you're re-traumatized, I think you either ignore it if it is repressed (and then you have another trauma to go along with whatever you've experienced previously), or you get a flare up of symptoms from your original event if you have remembered it. (flashbacks and nightmares of your first event)
Again, I'd like to echo what Hashi said, if you're at risk, call someone. The police, your psychiatrist, your therapist, people you trust. I suggest going to your therapist and your psychiatrist anyway, they can help with the risk of re-traumatization.