What did this dream mean?

I haven't watched that many TV shows or movies recently and I usually pass of weird dreams as a reaction to having seen certain things. This dream freaked me out a lot.

I was in my house but, in the dream, it wasn't my house. I was with two young boys and a man was lying on the couch. I am an adult and I knew this man was bad. He was watching the three of use while the owner was gone. I assume that in some way I was related to the owner. I knew all the sordid details of his personal life (in the dream) and I decided that I was the one responsible for protecting these boys and myself. I stood up and started yelling at him and telling him that I knew everything (that he was a paedophile) and that I wasn't going to let him get away with it. He didn't care but he kept grabbing my wrist while I continued to scream at him. I wanted the boys to believe me but they didn't say a word during the dream. When the owner came back, I ran into the kitchen to tell them what I knew and that he was bad. I saw myself in the dream for the first time and I believe that I transformed into a child in a matter of seconds. The child looked nothing like me. She had long, thin strawberry blonde (but closer to red) hair. She was wearing a purple hat and jacket. I was crying and trying to tell her but she wouldn't believe me. The entire time she kept her head down. I felt as though she thought I was making it up. I cried and cried and begged her to believe me but she wouldn't. Through the dream, "Anthrax" by Kimya Dawson was playing in the background.

I don't know any of the people I saw in the dream and I have never come across any characters such as the grown man.

Any feedback would be great because it scared me.

Thank you