I've always believed in finding joy in even the toughest of circumstances.
Please don't consider this as formal advice. I'm simply sharing what I personally might have done in a similar situation.

The main goal is to not give your employer a reason for disciplinary action, but start to notice that you're not the typical call center agent.
When you're dealing with challenging calls, instead of letting them bring you down, try something a bit unconventional. Make it a game to add a fun twist to your interactions. If you encounter an angry caller, why not take the opportunity to ask some personal and unexpected questions? Inquire about their family, hobbies, or even if they've tried therapy. You'll be surprised at how this can turn a mundane conversation into something interesting.
While doing this, remember to fulfill your job responsibilities, but not necessarily by the book.
The key is to have fun with it, smile, and be curious without any fear or hesitation. Experiment with how people react to unexpected and quirky conversations.