Dealing with molestation/rape

I need real advice on this. When I was 10 years old my stepdad molested me.... at least I think he did. He made me get naked so he could show me and teach me about my "lady parts". He used my finger to put inside of me so I could "feel around". He showed me pictures of penises and then made me watch him jack off. He told me he did all of this to educate me because my mother never would. Did he take a sex ed lesson to far or did he actually take advantage of me?(I was told he was raped when he was a little boy) I have blocked it out for a really long time. I have told some people recently, but not the most important one in my life, my mother. See I feel I cannot tell her because it would destroy our family. She has 3 other kids younger with my stepdad. They would hate me for taking away their father. They also would struggle financially seperated. (More resentment) The other really confusing part about this is I have always had to refer to my stepdad as dad. He raised me from 9 months old when my biological father walked away. So I am torn when I see my father walk the halls of my house. What is my 19 year old self suppose to think. "Hey there is dad! I love my dad, but wait I think dad did dirty things to me." None of my family understands why I grew apart from him... well this is why. So growing up I was told I was a little brat for wanting my real dad. Well lets add some more confusion. I met my biological dad last year (freshman year of college, yes I still live at home). Well now my family hates me more for excepting him into my life.... I am trying to save up so I can move out away from my stepdad. No one really understands why. I'm not sure how to handle this. The is just a piece of the cake. I mean I am a college student, I have relationship issues with my boyfriend. I am going through that stage where I am losing all my old friends because I realize they are no good for me. I am struggling....