How? What do thoughts like these look like?

Also, how old are you out of curiosity? I feel like there were a number of times I've felt like I was thinking something dark or deviant others avoided and decided instead to embrace it. It's part of growing up really. It sounds almost like the prototype of any psychological growth at all.

Don't be afraid of even the darkest things you will think. Find no shock, or horror, or guilt, and I think all such thoughts soften, because you are thinking softly. Dark thoughts are often just punishment anyway: dark pictures you show yourself to frighten yourself. Nothing is wrong with you and it doesn't mean anything. The dark pictures JUST ARE the thoughts that something is wrong with you and that you have reason to fear, and as you think, you see. Think softly, and they will go, just as a child is reassured by the love of a parent from a nightmare.