my stutter gives me so much anxiety and stress

my stutter gives me so much anxiety and stress Hello, I'm in highschool and struggle with speech blocks. No one says anything about because I don't have it super often but this friday one of my friends just mentioned it and suddenly a wave of anxiety hit me. I have no idea why tho, I can speak fluently when I'm calm and chill and take breaths but because of anxiety and these situations I can never keep cool at the right moment. Does anyone else get stress when someone just mentions your stutter and why is this? Also how can I keep calm when speaking infront of a class?