Disturbing, terrifing dreams???

So, in this dream that I keep having, there's this little girl about 4 or 5. It's a different girl every time, but it's mostly the same. She's yelling for help, and looking at me and shes crying. I don't really know where she is but as hard as i try i cant get to her. And then all of a sudden this big scary guy in a black suit comes out with a knife. I can never see his face but i know its a guy. And the worst part of this dream? Then he starts killing her. He'll slit her throat or stab her or something HORRIBLE and I'm forced to watch while shes screaming my name and begging for help. The dream never ends cause i usually wake up after that. I'm a 23 yr old guy and I really have no idea whats causing this. I get them almost every nite now. The only thing I can think of that might have triggered these is that I was molested as a kid, but only like 3 times and i dont remember it that well. Plz just tell me that somone else out there has dreams like this??