Pull, bring, etc. somebody up short
Definition 1 of 1
Pro Tip 1/3Sudden Interruption
Used when something happens unexpectedly, causing a person to stop what they're doing immediately. 
She started to apologize, but his glare brought her up short.
Pro Tip 2/3Emotional Impact
The phrase often implies that the person is surprised or affected emotionally by the interruption. 
The sight of the injured animal pulled her up short.
Pro Tip 3/3Not Literally
The stopping is usually metaphorical, not a physical halt. It's about stopping thoughts or actions. 
His confession pulled me up short; I had no reply.