Some people can have repressed memories. Sometimes we forget about traumatic experiences and then memory gaps occur.
Id suggest talking about your past with a professional and possibly asking your family about periods in your life which you don't remember.

However since you're so young I hope you can work with an experienced professional because there's a danger of creating "false memories" and or retraumatisation caused by remembering. You'll need coping skills and support system to go through that.
It's great that at the tender age of 16 you already have such advanced understanding of your problem, you seem like a highly intelligent young lady!