Lost V to stepdad, fiancé hates me

My mom was married to our stepdad for two years before he used to sneak and go into my little sisters room she was 10 years old I found out went to the school called saying that she was skipping class so I looked in her diary and yes I know invasion of privacy but I had to know if she was getting bullied or not because that is something I take seriously I didn’t wanna lose my little sister I changed her locks on her door and told her to lock it every night or sometimes I would sleep with her and he wouldn’t come in but then he found other ways to see her like pulling her out of class early and in the showerafter I found out I started throwing myself at my stepdad because my lil sis told me he had pulled a gun out on her and threaten to kill her if she told our mom . I was 15 years oldHe left her alone for a month while he was messing with me till she came to me and told me he was back going into her room so then I finally decided to tell our dad who had just gotten out of prison two months before our real dad came up to the house and beat up our stepdad and when our stepdad tried to stab him I grabbed a kitchen knife and stabbed our stepdad . When the police showed my dad said it was him and went back to prison and we got removed from our moms house my sister hated me and didn’t talk to me for a whole year. We got placed 2 different places . But we’d Facebook and stuff I did Hugo to her hs graduation and stuff . My sis is now 19 just finished her first year of college and I’m 24 now and engaged to my college sweetheart . He will be meeting my dad for the first time in a few weeks when he’s released and I didnt want there to be any awkwardness so a few days ago i told him EVERYTHING cuz I thought he should know because after all we are engaged. And he needed time to process it all he was gone a whole day and when he finally came around I felt he looks at me different. He says he’s ok and nothing to talk about but what should I do because I’m not ....