Hello. My first question would be why does the character have to stutter? Stuttering is not caused by nervousness or anxiety. An already present stuttering disorder may be exacerbated by stress and anxiety. I would caution to think about how this character may perpetuate negative or false stereotypes regarding the disorder that we have been fighting to change. I would say that it is not realistic and stuttering while anxious is a tired trope. There may be more creative and effective ways to express your histories character’s anxiety. Second question: Every person who stutters is different. Some become more fluent with alcohol, some it does not change, and others it may become worse.