what was the narrator unprepared to deal with in her situation? how does this make her feel?

Basically Offred is referring to spare time. She is bored. Offred sits in her room, waiting, and thinks about 19th-century paintings of harem women, about how women waiting is or isn't erotic. It's difficult to know exactly how she feels. The sex act has been divorced from emotion and human intimacy. Her role as handmaid has become routine and perhaps Offred wonders what feelings in the past might have been like.