Same here. Was in a wedding, and the best man couldn’t make it a month before the wedding. The groom asked me to be the best man and deliver a speech. The groom was one of my best friends and I didn’t want to let him down, and he knew I had a stutter. I could have backed out and made clear reason why and he would have understood. However I pushed forward, and agreed to do it. I practiced that speech probably 30 times. Turned out to be a major success. Got a lot of laughs and had a nice sincere message at the end.