"Before every performance, I think I am about to keel over"

In this quote, Brenda Blethyn is revealing her uneasiness before a performance. The phrase "about to slump" recommends that she is experiencing extreme anxiety and physical sensations of stress, such as lightheadedness or faintness. Using the word "every" also recommends that this sensation is consistent and perhaps continuous, rather than a one-time incident. This quote highlights the vulnerability and pressure that stars and entertainers can feel before going on stage, and how even successful and skilled people like Blethyn can still deal with nerves. It likewise highlights the importance of mental and emotional preparation before carrying out.