It seems you have several issues going on here. Like you said, you may never know who attacked you. Forgiveness is always your choice - but ultimately if you can forgive, that is what frees you from your attacker. Until then you are bound by your thoughts, fears, and so on. Just the words won't cut it. It has to be released from your heart (so YOU can be free- - not so your attacker can rest at ease; they likely won't even know).

As for your parents, there is much at work here - you're angry with them for something, they're not respecting boundaries or your emotions, feelings, thoughts. So there is the work around forgiving them, but also the work around them treating you with respect and not in further abusive ways. Of course forgiveness for them cannot come before the respect - that would be putting the cart before the horse. And they may never change. I too had to walk away from mine - but I couldn't until the financial ties were cut. That is a challenge.

I have not yet been able to forgive my abusers. I have been "on the fence" about it lately though - since not only am i getting dreams with my abusers in them every night, but I am also in a leadership, justice, and forgiveness class and having to face these issues head on. One of my abusers, i had been trying to forgive for the better part of 20 years (the lesser abuser of the 7) and still I have not. But, a step in that direction is that I no longer HATE her *all* the time. Sometimes i even have pity and sometimes compassion for her. It is a process and each of us can only go at our own rate.... best to you...
Kiya