Remember that Stoicism isn't about judging other people. It's not a moral philosophy you're supposed to project and enforce onto the world. No, it's a personal philosophy that's designed to direct your behavior. This is what Marcus Aurelius meant when he said: "Be tolerant with others and strict with yourself."

Be open to the idea that people are going to be fools or jerks or unreliable or anything else. Let them be. That's their business. That's not inside your control. But you have to be disciplined with yourself, and your reactions. If someone acts ridiculous, let them. If you're acting ridiculous, catch the problem, stop it and work on preventing it from happening in the future. What you do is in your control. That is your business. Be strict about it.
Leave other people to themselves. You have enough to worry about.