WTF?

I am a 45yo woman. I am single but have a boyfriend of 3yrs. I have two very beautiful, smart daughters age 23 and 22. I am also a survivor of CSA. 

I never really forgot about it, but never thought about it. In my mind I was 12 or 13 when the abuse ended so was around 10 when it started. Anytime someone would ask how old i was first time i had sex i would reply 12 or 13 and depending on how close i was with that person i would tell them it was sexual abuse. However, while visiting my aunt this past weekend she mentioned that it has been 35 years this month since he died. All the way home I thought but that means I was 10 when he died, how is that possible? I was 12 or 13...but if 10 when he died that means I was 5 or 6 when it started and he was full on f***ing me at 10 years old when he died.

For some reason that has triggered some very strong emotions. Like somehow that has made it all worse. I guess at 12 or 13 I saw myself as more mature to handle it so it was all good, I had done therapy(even told therapist i was 12 or 13) worked through some things and continued on with my life. Like I said, was always there, the knowledge that it had happened, just didn't want to admit to myself I was so young. Still a baby. 

I feel so stupid for feeling like this for the reason that I had thought I had dealt with it, plus what difference does it make I was younger? Some of the memories I am having though are more of my mom and how she handled the situation. Yes, she knew, because I told my sister who in turn told her. My mother asked me about it and I told her yes it was true, she then let out a big sigh and said well I guess I'm going to be dealing with DSS again, and guess I should call the cops. I was devastated in my mind no didn't want DSS there or the cops so I begged and pleaded for her not to and promised I wouldn't do it again...and she said okay and let him remain in our house. 

The abuse got worse then and he would use that against me, telling me if I told anyone again they would not only think I was a w**re but a liar also. So I just gave up and let him do whatever he wanted. 

My mom passed away last year. I love my mother very much. I forgave her for a lot of things simply because she didn't know any better. But idk if I can forgive this. I don't understand. Being a mother myself I would have and still would kill over my children. She knew this monster was attacking me and she did NOTHING because she didn't want to deal with DSS again? 

Anyway that's just a start of my effed up childhood and I now know I have a very long way to go in forgiving.