Is it possible to have been sexually abused as a kid, but have no memory of it?

Hello, I'm asking this question because for the past three years I've been wondering whether something might have happened to me when I was little. So the first time that I questioned myself whether I was sexually abused was after the first few times I tried having sex. I thought I was ready, but my body would just basically shut down. It took us (my bf and i) almost a year to actually have sex. This caused me a lot of stress and I cried a few times because I felt like there was something wrong with me and thought my body wasn't working the way it should. I'm more comfortable having sex, but everything changes the moment my bf tries to finger me. I instantly go into panic mode. This year, around August is when I took some time to analyze what really was going on with me. I recalled how when I was 4 and I already knew about masturbation. I don't know how I learned about it, but somehow I knew that it was something I should keep secret. I remember having sexual fantasies as a kid, which is weird because my parents never talked about sex or watched movies with sexual scenes when my brother and I were young. I remember feeling uncomfortable around one of my uncles because he would always kiss my cheek and hug me, and I would sit on his lap to watch movies even if it made me uncomfortable. However I don't want to jump into conclusion and say it was him because honestly I have no memories of it ever happening. In middle school I stopped caring about the way I dressed and never wanted to brush my hair because I did not want people to think I was trying to be pretty. Everything is so confusing. Has anyone ever experienced this? I wish I had someone I could talk to, but I'm afraid they would think I'm crazy or making things up.