It’s not just you, it’s much safer to read disturbing content than watch it on TV, it has something to do with how your mind forms memories. I think while reading your mind will on some level make up pictures to go with it, but only has access to the libraries of what you can already imagine. So if you have nightmares about it later or whatever it can still be challenging, but it’s hard to get as traumatised as you can by seeing images on TV/film or irl. My source for this is something my wife read while we were researching ways to help our little girl, who gets freaked out by certain things on TV very easily. It seems to hold true for her at least.