lose your grip on sth:失去(对某事物的)控制 be unable to control or do sth as well as you did before
she's definitely made some bad decisions recently. I think she's losing her grip.
她最近真是作了很多糟糕的决定,我认为她正在失去理智.
lose your head:become unable to act in a calm or sensible way 失去理智,恐慌失措
It's a very frightening situation, but we musn't lose our heads.
情况确实非常吓人,但是我们绝对不能慌张.
lose heart:失去信心,灰心,泄气 become discouraged
The revolutionaries lost heart after their leader was killed.
革命者们在领袖遇害后失去了信心.