The sentence "She fell to her knees and sank into a dark hole of despair and disbelief" contains a metaphor. The description of sinking into a dark hole is a metaphor for the emotional state of despair and disbelief.
This sentence contains personification, as it gives human-like qualities (the ability to groan) to the inanimate objects (rocks).
Personification.
metaphor
One example of personification in "The House on Mango Street" is when Esperanza describes the four skinny trees as “unclenched fists” reaching for the sky.
I was in disbelief when I found out my dog ran away
I look at the kids in disbelief for their terrible behavior.
She looked in disbelief at the driver who was yelling obscenities.
The man was in total disbelief when he found out he made the show.
Imagine my disbelief that you are trying to pass a vocabulary test by using the Internet.
For the sun rise not tomorrow.
to show disgust or disbelief.
Whenever I use disbelief in a sentence, I use it with another descriptive noun. "When she hit me, it filled me with pain and disbelief." See, it's not that hard. Just don't o looking for sentences to put it in, or else it will sound awkward and unnatural