I'm going to argue with my roommate about the laundry.
What is the disagreement you two have about the laundry?
I'm angry about it. I don't understand why I should do his job for him.
I see that you have a disagreement with your roommate. You need to have clear communication with a roommate about chores so that these kinds of disagreements don't happen.
I don't know if I can keep my anger under control.
Getting angry isn't going to solve anything. I think you should try to calm down, then have a discussion about the laundry with him. Nothing will change if you don't talk about it.