I am SO sorry that this happened to you! I was molested by boys when I was 5-ish and that carried enough shame, that I can't even imagine how much grief and pain that you are dealing with! I hope that you are seeking help, no matter what age you are! The earlier the better. I didn't start working on those issues until I was almost 50...not realizing that I had been affected for my whole life.
Beyond a shadow of a doubt, it was NOT about YOU! It was all about the girl who assaulted you, although you bear the scars, which ARE REAL! I believe that inner scars cause MUCH more damage than the visible scars do. There is plastic surgery, makeup, and scars are kind of like "proof" that you have been injured, if that makes sense?
There IS a taboo about the girl/girl abuse, which I would think is similar to a boy being assaulted by another boy, because of the stigma against same sex relationships. Being sexually assaulted is difficult, painful, and traumatic under ALL circumstances, ESPECIALLY when it occurs during childhood.
From what I have learned, shame seeps it's way into every part of us, physically, emotionally, mentally and spiritually! You didn't mention anything about whether you were raised in a church going home, or a home that didn't include church or God into the family unit. My dad was a minister, so I was raised in an environment that taught unworthiness, shame, and was taught the idea that if something happened to us, that it was somehow related to our relationship with God. That environment makes being sexually assaulted even more traumatic.
I don't know if my response is helping at all, but I wanted you to know that I am validating your experience, and the trail of pain that has followed you...PLEASE see a therapist that is trained in sexual abuse trauma? It will make ALL the difference in the world!
Blessings of peace sent your way!
AKJ