This is gonna be long TLDR at the bottom

Background: My(25F) relationship with my father as been very tumultuous. From ages 5-11 he molested me. When I got too old he moved on to a family friend that was like my little sister. We found out about her when I was 13. My mom asked if he'd done anything to me but I'd blocked it out at that point so I didn't say anything. My parents divorced of course but my friend's family didn't pursue charges. I didn't speak to him for at least 6 months because I was sad, confused and pissed about what he'd done. And even without the abuse he wasn't a very good dad. He was addicted to pain killers and didn't deal with any of his mental issues so even when he was at home he wasn't really there or would yell at us a lot. But I was also extremely attached to him(caused by the abuse) and we had good times so I didn't want to lose him. Eventually we started talking again and after a while I was allowed to have supervised visits while he lived with my aunt. During this time the unresolved trauma and inherited depression/anxiety from him started fucking with my mental health and my mom put me in therapy at 16 after finding out I was drinking to self medicate. In therapy eventually the memories bubbled up to the surface and I started dealing with the truth. I became pissed at my dad for the obvious of course but also because I realized he could've come clean with me and apologized but instead took advantage of me not remembering to pretend nothing happened. We had a therapy session together where I laid into him about how I felt and he apologized a lot. He told me he was also in therapy getting help(he'd been abused in the same way as a child). I took some space from him for a long time after that. We started talking again but not really hanging out. It was ok at first but I'd done a lot of healing at that point and realized this just wasn't good for me. I didn't feel good after talking to him and I knew he could never fix what he'd done to me and it wasn't worth it. Last I heard from him was over a year ago when he had heart surgery and I'm ok with that. I don't even know if he's alive since he stopped texting for holidays and my birthday and I don't feel bad. So that's where we are today

Now my aunt(his sister) is interesting. She's extremely introverted and doesn't need much to be happy.She's not a huge kids person but growing up she did some children's activities with me and I always had fun with her. As I got a little older she wasn't sure what to do with me so we mostly saw movies together or played games.I love her but it's always been a little awkward hanging out with just her. But she cares about me a lot and has always shown that. The problem is her and my dad look, sound and act almost exactly alike. And when he lived there is when the memories started coming up. She kicked him out and has moved since but it's still hard being around her and talking to her.I didn't even realize I was distancing from her for a while I just sort of stopped answering her, stopped coming over etc. Then I sort of understood why and I feel guilty because none of it is her fault and she has so little family left but I can't do it. Everytime she texts me I just get filled with dread. And it's become a cycle too where I feel top guilty to respond which only furthers the guilt. I feel like a bad person but she just has too much connection to him for me.

TLDR; Dad sexually abused me for most of my childhood, our relationship was weird for many years and I've gone no contact but his sister is so much like him and I associate them with eachother that I can't hang out with or talk to her anymore and I feel really shitty about it because she didn't do anything wrong.