I have no direct advice to offer but I thought it might help to tell you about my experiences.
I was abused as a child by a friend of my parents, firstly when he stayed in our house and a few years later when we stayed in his. When I told my mother about it as a teenager it was clear she knew something about it already, though I'm not sure how, which was a horrible feeling as she had never approached me about it or checked if I was ok. She then went on to tell me about an incident that happened when she was a child in a sort of "see, it happens to everyone" way, and said I should forget about it. She also strenuously insisted that I not tell my father about it. That reaction, basically the "it's nothing, get over it and tell no one" reaction, did far more damage IMO than the abuse itself because my abuser had no duty of care towards me while my mother did and still does to an extent. She would rather pretend it didn't happen than help me in any way. Unfortunately this seems to happen a lot for people who reveal abuse. I don't know why but people seem to want to shut it away and forget about it. I suppose it makes them uncomfortable.
Luckily for me my DH (just a new bf at the time) was willing to listen to me talk about it for hours on end. He was upset and angry about what happened. In fact one time he said "If I saw that guy I'd kill him, I really would," and that more than anything helped me at that time. For the first time I felt like someone cared about what had happened and that it really was horrible and wrong. I had some counselling at the time but unfortunately it didn't go very well. The first counsellor I had was horrendous. Basically she didn't listen to what I said, gave me pointless "exercises" to do which didn't help and implied more than once that it was my "trusting nature" that contributed to the abuse happening. It sent me back down on a spiral of self-loathing and I broke up with my DH (then bf) and things went severely to shit.
Then I found a better counsellor who really was an angel to me. Because of my previous experience with the other counsellor I didn't talk about the abuse directly, mainly about how I felt and about the break up. With her help I saw that I had rather strange ideas about myself, that I felt unworthy and useless despite a heap of evidence to the contrary. As a result of that counselling I regained enough self esteem and stability to go back pretty much to normal and more importantly to get back with my wonderful DH (who was kind enough to have me back!)
I sort of put the whole thing to bed as best I could at the time but about 5 years later it all suddenly came back to bite me on the ass. I became depressed, more severely so, and I told a friend about what happened. He was great and very understanding. Again his upset reaction helped me. Foolishly I tried to talk to my mother about it again, and again she dismissed it. I can't forgive her for that and in some ways I consider her refusal to help me worse in a way than the abuse. I'm still working on getting over it.
Like you I felt ashamed. Telling understanding friends about it really helped to lift that shame. Another friend I told actually cried and I was shocked. I asked him why he was crying and he said because he was imagining how he would feel if it was his step daughter it had happened to (she was a similar age to the age I was when it happened). That made me see it from another perspective.
As others have said, you are interpreting the abuse through adult eyes but when it happened you were a child. You were taught by your parents to respect adults and you sought adult attention just like any other child. You had no training whatsoever in standing up to someone, especially not someone that everyone liked and respected. You were following what you were taught - listen to adults, especially one who is kind and generous.
Something very hard to admit was that I liked my abuser, genuinely liked him. I craved his attention. I know that was partly because I got no physical affection from my parents and I was starved for it. I won't go into detail but my mother was also unwittingly complicit in a major part of the abuse. I say unwittingly but really looking back she should have known better. She should have known that a grown man showing interest in a young girl wasn't appropriate. I did protest by the way but I was told not to be so difficult. I hang on to that, the fact that I tried to stop having to go with him but was dismissed. I did try, but what could I do? My trusted parents were telling me it was what I had to do. I was a good girl who did what she was told.
I do still find it hard to talk about but I don't feel ashamed any more. I was a victim of a crime. I can understand people being uncomfortable hearing about it as it's a difficult topic that isn't widely talked about but that's their problem not mine. I don't go around telling everyone and anyone about it but my close friends know about it. For the most part they have been fantastic in supporting me and listening to me.
Sorry for waffling on but I hope my story helped somewhat. If you have any questions feel free to ask.