Worst deepest darkest secret

I’m so ashamed of this and it’s my darkest secret I have been keeping only a few people know this and I am posting this anonymously for that reason. I’m 26 years old now and I’m a female when I was younger I used to be in a foster home with my brother and sister I was molested by my foster father and my younger sister was molested by my foster mothers father. I was super young maybe 6 years old and me and my sister who was super young as well would do oral to each other we didn’t know what we were doing and I’m so ashamed of it to this day. I don’t talk about it at all and I try not to think about it but I’m so disgusting with myself because I’m older then my sister.