Maybe practice what you want to say while singing it. I pretty much never stutter when I am singing, and I sing to practice presentations and stuff. Also, don’t think about stuttering as much as possible even while you are stuttering in front of people, don’t focus on it, just accept it’s happening and keep trying to say what you want to say. Honestly, for me it takes regular public speech to improve my stutter. If I go a while without going out of my comfort zone as far as speaking; I can notice my talking gets more difficult. I know you can overcome any challenge you face. It sounds like you have already come pretty far past your struggle. I feel like the difficulty stuttering has added to my life makes me more ready to overcome. Stay strong!