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.
heart sinks, one's
One's courage or hope fails; one is very disappointed or dejected. For example, An hour before the picnic I heard thunder and my heart sank. This expression was first recorded in 1605 but was preceded in the 15th century by one's heart is at one's heels or in one's hose or in one's shoes . The present (and only surviving) usage was first recorded in 1605.
your heart ˈsinks
used 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