I think at the heart of it is that you're a 19 year old woman, recently entered adulthood and in the midst of university. There are a lot of changes and unknowns in your life right now, so even if you're not actively exhibity nervousness at a given moment, my bet is there is still a lot of underlying stress, below the surface. Most of us stutter more when our bodies are stressed. Kudos to you for taking a leadership role! Remember, stuttering does not define you, you define it. And yes, you may get some bad reactions on phone calls, but then other times we can also catastrophize the call as well. Best way to deal with it? In my opinion , it is to accept those moments of stuttering and tell yourself it's ok. Don't let it create avoidance behaviors. The stutter will snowball. Life begins at the end of your comfort zone.