This exact same thing always happens to me when i watch a scary movie. There really is no 1-size-fits-all remedy for this that i know of, but some stuff that helps me is
1. Religion (im deeply religious, if you're not, disreguard this)
2. Willing yourself to forget (self explanatory, repeat "I WILL FORGET" mentally, for example)
3. Time (these things pass in time, just wait for your mind to naturally get over it)

I hope these helps, these things usually work for me, and, with any luck, youll get lucid soon and be able to shoot that scary face