I am sorry this happened to you. And i believe it did. Something similar happened to me when I was a child. The times I can recall it happening, I was 11 and 12 years old. I would go to bed with my pajamas on and wake up completely naked. This happened on a semi regular basis.It always confused me but I never thought anything more about it except it was weird.

Then once, I kind of woke up. I was in a daze. My room was very dark because it was a makeshift room in an undeveloped basement. I thought I saw someone. A thing. A monster? I was terrified of monsters. It was definitely "someone" made of shadows. It was the sound I heard that woke me up. I'm sure I don't need to describe the sound. There was another sound. A sort of grunting sound. That's why I thought it was "The Monster". It wasn't loud but it was audible enough that it disturbed my sleep.

I remember touching my skin and feeling ashamed. I wondered where my pjs were and started to make motion to find them. It was so dark. My hands cautiously swept the empty bed around me. I was too close to the edge and I jumped back to the middle of the double bed.

Then I heard, "You're just having a bad dream. You must be so hot that you took your pajamas off. Go back to sleep."

I was so tired. So inexplicably tired. As I was drifting back to sleep the shadow blended into the darkness of the basement.

I had many times like this where weird stuff that I couldn't pinpoint happening. Sleep walking. Talking in my sleep. All kinds of stuff. I only remember that incident that clearly because I realized that that was the first time I had ever recognized that what ever that was, it was not okay and I was angry.

but I had no one to tell. I tried to tell my mom. But she told me I was lying and I was a slut. Even though I had no idea what that was.

I hope you go to therapy to talk about your story OP. I have been going to therapy of various sorts for the past 25 years. It really helps.