Feeling overwhelmed by childhood trauma and I don't know how to overcome.

I am 26 (m) now and recently had memories coming up that mess with my mind. When I was young, I was sexually abused by my older sister. Later on, I saw my cousin brother abusing her too, except it looked like she went to him willingly. Seeing that made me feel this weird, messed up jealousy because she was so close to him.

My whole life growing up has been completely messed up because of this.

Even now when I see couples, I get extremely jealous. I honestly do not know how to get rid of these thoughts of unhealthy jealousy. I just want to know if anyone else has been in a similar situation or how you even begin to process something like this.