Fellow in house left causing actor to stop performing (5,6)
I believe the answer is:
stage fright
'causing actor to stop performing' is the definition.
(stage fright might prevent an actor performing)
'fellow in house left' is the wordplay.
'fellow' becomes 'f' (abbreviation - of a society etc.).
'in' is an insertion indicator.
'house left' becomes 'stage right' (house left is stage right in a theatre).
'f' placed into 'stageright' is 'STAGE-FRIGHT'.
(Other definitions for stage fright that I've seen before include "attack of nerves" , "Pre-performance nerves" , "Nerves in front of an audience" , "Dramatic nerves" , "problem for players" .)