Am I guilty for this? Should I let go of the past?

TRIGGER!

Me and my sister were sexually abused by my fathers brother. He lived with us, my sister was 5 when she remembered and I was 8. Idk if my memory blocked it out before that but was the first time I remembered but something inside me feels like I was abused way before...

That day it happened I talked to my sister she was only 5 but she understood everything I said and she told me he did the same thing to her so I grabbed my sisters hand and we went to talk to my mom and dad and told them. They didn’t believe us and since then I never mentioned it to them until fast forward a couple of years I found out my mother was having an affair with the man that abused us the whole time can you imagine how that made me feel? I felt more bad because my sister was only 5.

Since then me and my mother never really had a good relationship she was a very toxic person she would also sleep with a lot of men at home meanwhile she’s with my father. I’m the oldest I’ve witnessed and seen many things she’s done. I left home cause I couldn’t take it anymore she was trying to marry me off with some man I didn’t even know only because he “had money” I decided to leave with my now husband. I’m 33 now and sometimes as much as I try that relationship with her isn’t good, she’s very old and sick and I feel bad I try to have that connection with her but I can’t and part of me feels like the only reason I can’t is because she never ever sat down with me and talked about what had happened to me and my sister, she never apologized for it or at least sat down with us and be there for us as a mother knowing your daughters got molested by the man you were having an affair with, I needed something.

One day I got into an argument with her and I just decided to cut her off for a little I stopped talking to her for a week it wasn’t even that long and my brother starts calling me telling me a whole bunch of things how I’m disgusting for treating mom that way and that he doesn’t want to hear from me anymore to forget about him. I said fine I wasn’t going to stress over him since I’m currently pregnant.

10 minutes later my sister texts me as well telling me I need to get over what happened. How am I supposed to get over it? How? I can’t get over it how can she even tell me that she got molested by that man as well! She’s making me seem like the bad person because i won’t forgive my mom or maybe I am a bad person for that. She told me I need therapy that mom is old and I need to let the past go and I just felt bad my mom called them crying that I wasn’t speaking to her and that’s why they started telling me things so I just decided to stop talking to my sister also I was already so stressed out because of my pregnancy I didn’t need anymore stress from them and now I feel like I’m forced to speak to my mother everyday..

Am I wrong for being this way? Sometimes I feel guilty like maybe I do need to get over it