Easiest thing to solve is the issue with your friend. Tell her you're not OK with it. That might lead to a whole discussion where you can unburden some of your feelings. Next thing is this. You stutter. Don't avoid it. Go ahead and stutter. We amp up how we feel about the stutter, but we don't consider what it costs us be avoiding things. You have things to say in class? Say them. Speak up. Share your ideas. This won't be easy. It's going to be so very hard. We condition ourselves to avoid speaking. To change that programming takes a lot of time and effort. Finally, speech therapy. Many of us have had inadequate speech therapy. Few among us have had competent, professional speech therapy. Seek out speech therapy with an SLP who specializes in stuttering (Speech Language Pathologist.) If they offer tips or tricks, keep looking. The therapy I received was a "ground up" approach. Teaching me fluency in the office sessions. Having me practice skills daily in private. Achieving fluency and confidence in the office setting before applying the skills in the real world. If you were learning to play a musical instrument, your teacher wouldn't have you performing in front of others when you are first learning. You get lessons once or twice a week, and you practice in private every day. You don't do a rehearsal until you're ready. IMO, good speech therapy is a lot like this.