breaking point
noun /ˈbreɪkɪŋ pɔɪnt/
  /ˈbreɪkɪŋ pɔɪnt/
(also break point)
 [uncountable]- the time when problems become so great that a person, an organization or a system can no longer deal with them
- to be at/to reach breaking point
 - to be stretched to breaking point