Wow....I cannot tell you how relieved I am for you, J. In most cases, parents (especially, single parents) will understand what has happened to their child, though there are some that take the side of the abuser/rapist. I truly pity those parents and the innocent victims.
You are a valuable human being and you have something very important to do in your lifetime. I don't know what it is, and I can't say if it will tie into your terrible experiences. What I do know is that a child as brave, honest, and courageous as you are has "Something Important To Do."
Blessings upon your mother - I can imagine her sense of guilt because I carried my own for what happened to my sons for many, many years. Thank goodness you're both in counseling - she will have her own healing to do, and you yours. You will not be able to heal for her, but she'll lean on you a great deal in months to come for a great many reasons. Never be tempted to speak accusingly to her about your horrific ordeal, no matter how angry you get with her. When it comes to that point in your healing, scream it at your counselor and get it out, but never use this against your mother to get even or deliberately harm her. I have a feeling that you wouldn't do this, but it's just a reminder to you.
As for feeling dirty? You're allowed to - what that Thing did to you was cruel, sick, and he'll get what's coming to him when he enters prison, I promise you. Having said that, keep in mind that what he DID was filthy, but you, dear child, are not dirty, at all. These feelings are normal and will soon be replaced by understanding and acceptance that you were the victim of a sadistic Rat Sh*t - you will come to terms with these feelings, in due time, and move forward on a positive healing path.
There is NO DIFFERENCE between a male or female victim. The only difference is gender. A victim is a victim, and I'll say that it is a personal mandate for me to respond to people who have suffered cruelties at the hands of another human being, regardless of gender, race, creed, sexua| orientation, etc. If just one person breaks the cycle of violence and abuse, that's one person out of that wheel and, one day, the cycle of violence and abuse will collapse as a socially accepted behavior.
As Blue Rose has asked, please post back as time goes on. And, always remember: you are a very valued and loved human being, and you have something important to do in your lifetime.