I'm upset with my best friend for taking photos of two workers at our school
Why would them taking pictures bother you?
We agreed that she wouldn't take pictures of us without informing first.
It's good to let your friends know when they've done something to bother you. That way they know not to do it in the future.
I can't talk to her about it. I'm too angry.
I understand that you're upset, but you should really try to calm down and then talk to your friend.