Maybe I'm blind, but... Where is the fantasize menu? Is it in-game, or do I have to quit to access it?
Go to the Repair module back in the storage module! It's under those options, as mentioned by B4B3. Repair > Fantasize, as it's a method of restoring Focus.
You can either get it done with quickly, or use it as a thematic link to the gallery - hence, the Fantasize menu. Also thematically reframes them as fantasies, which can make some more hardcore content more digestible for some people.
Enjoy!