Do you think I was sexually abused as a child?:(? Long description. ?

I think I might have been sexually abused as a child. When I was younger I remember always humping things like pillows and stuffed animals. I also would hump my little sister. I know that sounds weird and gross but this was when I was young and didn't know better. My parents did foster care and we had a little girl and I would hump her too. I never wanted to I just did. And I never knew why I still don't know why to this day. This wasn't just a one time thing. I did it all the time:( I don't really remember but I think later on when I got a bit older I knew better not to do it but I still did. I'm just confused. How did I know that it was going to make me feel good? I don't remember anything happening to me as a child, but I do know that my mom was sexually abused as a child. So could she have done something to me when I was young enough to not remember? I don't think it would have been my dad. I'm a huge daddys girl. But I do remember my older sister being on top of me when I was little But I don't remember what she was doing But me and her are like best friends. So it couldn't have been her right? But if it was I'm still wondering why she would have done something like that and it leads me back to the fact that our mom was sexually abused So could she have done something? What brings this up is my little sister just asked me why I use to do that to her. She's deaf so it's not like she can tell anyone but I can understand her sign language And she asked why I did it. And I lied and said I didn't do it. And we don't have the other little girl anymore that I use to do it to. She got adopted And I'm scared that she's gonna remember one day and tell someone And I don't want anyone to know. I don't want to get in trouble. Im now 17 years old and it's been a very long time since I've done anything. But it still makes me sick to my stomach that I ever did it. What do you think caused this? And please do not leave any bad comments. I'm not a bad person...