To childofaking: My oldest daughter is only a couple years younger than you are and i don't let her have free reign of the internet or youtube for that exact reason.
I'm so sorry you watched something that upset you so bad! I bet it was really awful. Please please be very careful next time what you watch, these things are very hard to get out of our minds.
I suggest watching something that makes you laugh, or call a friend and talk about something fun. I'm praying God's peace over your mind and thoughts. The best thing to do is pray then get your mind off of it the best you can, when those thoughts come, do not dwell on them, pick up a book and read, text someone, watching something you really like.
*hugs* You're ok and this will pass
Again, please be careful what you look at and watch!