Please I need help: How to understand this paragraph from essay?

Greetings, this is the part 3 of the paragraphs that I need help with. This is for my report in English. How do you understand this paragraph?

This is from the same essay "Why First Night Seems Like Last Night" By Cornelia Otis Skinner. This is about the stage fright of an actress who will have her lead role in a play for this first time. This the 21st to 23rd and 25th paragraph.

" You may be appearing in a long-run success, assured and cool as a cucumber, when all at once you hear another actor saying his lines and it's as though you were hearing them for this first time and you think, "what do I say when he finishes talking? What the hell is my next speech?" and you may go into a frozen paralysis which prompter or fellow players rescue you by throwing you a cue, although mercifully more often habit or the subconscious produces the elusive words, which come forth automatically and often in such hollow tones you have an illusion that a complete stranger is saying them.

" This Gehenna anticipating lines can become epidemic and run through an entire company. Last season in Major Barbara, it was solacing to find out that a seasoned veteran like Charles Laughton came successfully came through an attack; and when, one evening, Eli Wallach went up in a line he knew backward(and was about the way he said it too), I felt better about the moment when I looked with a wild surmise at Glynis Johns, who played my daughter, and couldn't for the life of me think of her name.

I, who behind the exterior appearance of a lady am at the Wife of Bath, occasionally become the victim of another long-run neurosis, namely the dirty-word complex, in which one realizes that by mere changing of a letter or two or the shifting of a simple noun or mild adjective.

I have yet to play a part in which there is not the possibility of one of these verbal pitfalls. The terror of falling into one can become an obsession. As the sentence involving it approaches, I have found myself breaking into a clammy sweat. Am I going to say it? please, God, don't let me say it! And, even after the line has been delivered, I'll sometimes think, Did I say it? And, even after the line has been delivered, I'll sometimes think, Did I say it?"

Paragraph 23 and 24 is not complete because the last part of the paragraph is understandable. All of the paragraphs are just connected to each other and I didn't include paragraph 24 for she only stated some examples. I don't understand the symbols that she is using and the humor she is trying to imply. I think those people who are native English speakers or writers can understand. There's the last part guy, only 2 paragraphs left. Thank you so much and I'm sorry that it's long. You can summarize it or just state the main point of every paragraph and the symbols she's using like the verbal pitfalls. Or if you could please just convert it to simple English that is easy to understand. the same issue with the first part I posted.