Hey all!

Well, I have a niece who's almost 2 years old, and I really really love her from the bottom of my heart, but my brain always imagines her being hurt, in many ways, and my brain repeats her voice as she screams in pain, and an entire scene is constructed in details, and might go to even deeper details and more images as it stays longer in my brain. I try to stop this in any way, but I can't, and even if I manage, it gets back the day after and so on and so on. Sometimes I hear her voice if I'm in my room, and I jump in fear, thinking that there might be something wrong, and I run to her only to find her playing.

Any advice at all as to how to get rid of this? I have tried a lot of stuff, since this is a daily issue and I have to stop it in any way to maintain my sanity. But can you help me?