collapse, fall, etc. in/into a heap
fall into a heap
To become very emotional, especially sad, and perhaps to literally hunch over as a result. Poor Jane really fell into a heap during the funeral service. I can't watch those sappy movies because I just fall into a heap every time.
collapse, fall, etc. in/into a ˈheapfall down heavily and not move: He collapsed in a heap on the floor.
See also: heap