sink into despair
To enter into a state of utter hopelessness, helplessness, and depression. I sank into despair when I was told I hadn't gotten the job. We can't sink into despair just because our sales figures weren't what we were hoping for—we've got to pick ourselves up and do what is necessary to get back on track!
sink into despair
to become depressed; to become completely discouraged. After facing the hopelessness of the future, Jean Paul sank into despair. Mary sank into despair upon learning of the death of her grandmother.