One time I got called to come in and fill in for an actor who couldn't do the show any longer, a play, and I had basically three days to memorize the entire show. Wow, that was so stressful because I really had to cram that in and you've got to be dedicated and committed to getting it done.
I would say the most stressful experiences for myself have always been more of an internal battle that I have with pressure that I put on myself. Especially if I have maybe like a hard or emotional scene that I know I'm filming the next day or that day. A lot of the times I will stress myself out so much about it that when it's time to do the scene I just I can't fully deliver because I've built such a barrier in my mind of not being able to cross it or a fear of being able to cross it. So usually it's an internal thing. The only other stresses I usually have on set are just if like the other actors don't vibe with me but you know that's a short-lived problem. Internal battles are are more the things you got to work on for long-term success.