touch (rock) bottom
To reach the lowest or worst point of a decline. Primarily heard in UK. I knew I had touched rock bottom when I missed my son's birthday party because I was so hungover. That's when I knew I needed to get help. Prices have been falling for weeks during the crash, but the economy has finally touched bottom.
Reach the lowest point, as in During the recession the economists kept saying that we hadn't touched bottom yet. This metaphor for reaching the ground under a body of water has been used since the mid-1800s.
touch bottom1 reach the bottom of water with your feet. 2 be at the lowest or worst point. 3 be in possession of the full facts. British
1 reach the ground at the bottom of an area of water
2 (British English) reach the worst possible state or condition: Her career really touched bottom with that movie.