From Longman Dictionary of Contemporary Englishbe at/hit/reach rock bottombe at/hit/reach rock bottomWORSE a) to be in a very bad situation that could not be any worse I was at rock bottom, and knew I had to try and stop drinking. b) to be at a very low level We bought the house when prices were at rock bottom. → bottom
Examples from the Corpus
be at/hit/reach rock bottom• By four o'clock Melissa's spirits were at rock bottom. 