There's similarities to my childhood here OP. My parent's weren't abusive or neglectful but they did take their eye off the ball, had flawed parenting techniques and were too trusting with any adults around their children - not only that, we were drilled to be deferential and do any adults bidding. I experienced SA as a child. It was handled badly by the adults involved- parent's and the GP, who reassured them I'd forget it due to my youth. And like you, the abuse gave me some sort of vulnerability that made me a target for other abusers in my teens and also abusive partners.
Like others here, I got counselling in my twenties which helped a lot and I did discuss it with them. The difference between my parents and yours was that I knew that they really believed the advice of the GP. We had, I suppose, the kind of conversation that you'd like to have with your parents. They were horrified that I'd always remembered, they were full of remorse and regret that they took the flawed advice and apologised. But, from the sounds of your parents, I don't think they are capable of that.
It was a helpful conversation for me at the time, but my mother since then (Dad has died in the interim) has seemed to block out any knowledge of my abuse, even though she was made very aware of it- for example, my son had this occasional mannerism as a baby and my mother joked he was like John when he did that. My abuser. FFS. Another time she declared that while she was not a perfect mother, at least she could go to her grave knowing none of her children ever got abused. 
I was stunned and reminded her about John when I was around 7, Tom when I was 14, and Jerry when I was 16. All men who were as old, or older than my parents. I can't tell you how hurtful that was - how how could a mother forget their child was sexually abused repeatedly as a child and was targeted by two predators in her teens? It's possible that because it never progressed to rape in any of those situations, that it's not on her radar as anything of any importance...I don't know.
I will never mention it again to her. She prefers to believe her own version and honestly, it does affect how I feel about her now. She's baffled that we aren't as close as she would be to my other sisters but trying to explain why would be dismissed so why put myself through the fact that not only did they fail me at the time, but any remorse was short-lived and by denying it subsequently she only failed me again but this time I've the benefit of motherhood myself and I know what I'd do for my child so I judge her hard for that now.
I think it would be different if Dad was still here because he understood much better how abuse affected me, was able to see past things click into place and he was extremely protective of me as a result until the day he died.
And what I've discovered in the 8 years since my mother said that stunner to me, - and this will be important for you to know is that I don't need her input to heal or thrive. I actually never needed it and in fact, involving her probably only set my recovery path back quite a bit. Dad's reaction helped me because he got it. She never did so it was spectacularly unhelpful to me. I've fully healed from the effects of abuse I think, but tbh, knowing that my mother now knows all the details yet couldn't give a fuck really threw me backwards into a spiral for several years and I worry that would happen to you if you tried to talk to your parents. You can heal without them - in fact, they would quite possibly hinder or damage the progress you've worked so hard towards.