I'm going to call my fiance a drama queen
What makes you think that she is a drama queen?
I don't like it when he tries to make grandeur things into grandeur things.
Context and tone go a long way when criticizing a partner. Being called a drama queen may upset him if he doesn't realize his behavior is annoying you. Talk things over before saying something you can't take back.
He's just stressing on things and sometimes need to be reassured that there is nothing to worry about.
Well, calling him names is not the way to achieve that. I think that trying to talk calmly about the situation is the way to go. It is wrong to call a partner rude names.