Update:

Talking with my mom tonight with questions pertaining to my fragmented memory, I uncovered more of the memory.

It wasn't in MY room, but in my grandparent's room when my sister and I would stay over there until late at night every once in a while, while my parents were on a date. I think I know who it was that did it, as the blob started taking on physical characteristics of this person (ie, I now see curls, and what I think are earrings).

I'm also now having more fragmented memories in conjunction with the main one, where I remember dark red acrylic nails, and an incident at a friend's house where I was alone in a dark room with a door open (similar to what I now remember of this potential abuse) during a sleep over, and I had my first panic attack and uncontrollably began screaming and crying as I ran downstairs.

In the memory of being at my friend's house, I remember being absolutely terrified of someone coming through the door to hurt me.

I'm remembering more, though I would still appreciate very much if any of you could give me some advice on how and maybe when you remembered anything of your past. This experience is nothing like last year. I feel like I'm in open water and I'm trying desperately to remember how to swim.