be on a roller coaster

To be experiencing swift and sudden changes in both positive and negative directions. Likened to the tumultuous movements of a roller coaster at an amusement park. My bank account is on a roller coaster these days. As soon as I get paid, I have to pay all these medical bills. Her life was a roller coaster after she graduated from college, filled with ups and downs as she tried to establish herself as a fashion designer. The president's approval rating has been on a roller coaster ever since details of the scandal began to emerge.