What word that sounds somewhat like "carpenthy" which is used to describe an emotional crutch for example Linus's blanket in Charlie Brown? I feel like I learned a word like this eons ago and poof I can't find it anywhere. Perhaps I dreamed it.
It seems too obvious given the reference to Linus's blanket, but a common term for this is security blanket:
1 : a blanket carried by a child as a protection against anxiety
2 : a usually familiar object whose presence dispels anxiety
// Alabama’s receiving corps is the best security blanket a new quarterback can ask for, but just how much does the Tide coaching staff trust Jones to throw the ball?
— C.j. Doon, baltimoresun.com, "Can Wisconsin bounce back? Will Auburn hang with LSU? Most intriguing college football questions for Week 9," 25 Oct. 2019
It's the second sense that has a broader application.
To address a comment, I find the words security and carpenthy to sound very similar. I might use them in a rhyme:
"My blanket offers not carpenthy, but instead provides security."