Here's the answer:
“我真想找个洞钻进去”
(wǒ zhēn xiǎng zhǎo gè dòng zuān jìn-qu)
Watch a real native speaker say it:
Here's how it sounds in a textbook:
Fun fact: the hundreds of thousands of people learning Chinese with Memrise get this phrase correct 83.82% of the time!
