I'm at my wit's end.

Meaning

I'm completely exhausted and unable to cope.

Examples

• John: I've been trying to fix this computer all day.
• Alice: Oh dear! I'm so sorry. Sometimes I'm <b>at my wit's end</b> too.
• John: Nothing seems to work. I'm totally frustrated.
• Alice: I understand. Dealing with computers can make anyone feel <b>at my wit's end</b>!