your heart sinks
(One) feels disappointed or disheartened. My heart sank when I saw that the meal I'd spent all day preparing had burned in the oven.
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
your heart ˈsinksused to say that you suddenly feel sad or depressed about something: My heart sank when I realized I would have to walk home in the rain. OPPOSITE: your heart leaps
Farlex Partner Idioms Dictionary © Farlex 2017