Who is The Raven Queen?

This last week, my party and I traveled to the Shadowfell, or so I was told it is called. When I say traveled, I mean Scree and I walked behind a tree and were transported without our knowledge. It was a dark, gloomy, and and somewhat desolate place which makes me wonder WHAT THE HELL AM I DOING wanting to know more about her? The thing is, I have already served a dark lady, I do not wish to do so again, but Lliira cannot restore my memories. Fip and Erik told me that she keeps memories in that castle of hers. It is even called "The Fortress of Memories" according to them. As if that is where memories go when they are taken.
 
Well, taken is exactly what my memories were. I have no good memories until recently. I was made into a shell by Elaria Duskmantle. That elf stole my memories, now it turns out another elf may be holding them? What is it with me and getting screwed over by female elves? We just lost Temperence, another female elf, to the Grim Hollow and that has hurt my heart. Despite her goody two shoes ways, she was a goody two shoes friend.
 
Her loss has deeply affected my other friend, Fip. He's trying to find himself at the bottom of a bottle. I haven't removed his alcohol because I don't wish to piss him off while he grieves, but I check up on him each night. I'll cast healing or restoration spells on him so that he doesn't flirt with alcohol poisoning. I have even drank with him, just so he will talk about it. I have been in his shoes, I was drink for a few years after my time with Elaria. I try to soothe him to sleep just so he quits drinking for the day with music. Sometimes it even helps. I don't know what else to do for my friend. He will either get through this, or it will destroy him. I'm trying to support him so it is not the latter.
 
During the day I am researching everything I can on the Raven Queen. I have even sunk a bunch of gold to have access to private libraries I have been told about. It may cost me 700 gold pieces before the week is done. I just hope that this is all worth it in the end. I want to know who I was, what I did, who was that female elf I saw in the Shadowfell when others saw their loved ones? I believe the only thing that kept me sane was not knowing who jumped off that cliff so that I could try to stop the others. Lliira be with me as I try to find these answers. I worry for my friends and I pray that we will be safe from here on out. I don't know how many more friends I can lose.