Go off (one's) dot verb phrase
If you go off your dot, you are insane or mentally unstable.
Why does Janet go off her dot easily these days?
You must be off your dot if you believe in what she said.
Mom will be going off her dot if she sees my brother’s messy room.
I’ll end up going off my dot if I have to work in this cubicle for one more day!
Stupid or crazy
If you're off your trolley, your ideas or behaviour are crazy or insane.
Suddenly become crazy or very angry or lose control
Totally insane; overflowing with emotion, especially rage or enthusiasm
The verb "go" should be conjugated according to its tense.
To tell someone the truth about something that they had not understood or received false information
I have to set my wife straight about what happened yesterday.